Computer Fundamentals
Unit-III
Software: - A computer
can not do anything on its own .It must be instructed to do a desired job. Hence,
it is necessary to specify a sequence of instructions that a computer must
perform to solve a problem. Such a sequence of instructions written in a
language that can be understood by a computer is called a computer program. It
is the program that controls the activity of processing by the computer and the
computer perform precisely what the program wants it to do. When a computer is
using a particular program, we say it is running or execution that program. The
term software refers to the set of computer program, procedures ,and associated
documents (flowcharts, manuals ,etc) that describe the programs and how they
are to be precise ,software means a collection of program whose objective is to
enhance the capabilities of the hardware .
A software package is a
group of programs that solve a specific type of job .For example, a
word-processing package may contain program for text editing, text formatting,
A graphics, spelling checking, etc. Thus a multipurpose computer system has
several software packages one each for every type of job it can perform.
Relationship between
Hardware and Software:-In order for a computer to produce useful output,
the hardware and software must work together. Nothing useful can be done with
the computer hardware on its own and software cannot be utilized without
supporting hardware.
To take on analogy, a
cassettes player and the cassettes purchased form market are hardware. However,
the songs recorded on the cassettes are its software .To listen to a particular
song, first of all that song has to be recorded on one of the cassettes, which
should then be mounted on the cassette player and played. Similarly, to get a
particular job done by a computer, the relevant software should be loaded in
the hardware before processing starts. The following important points regarding
the relationship between hardware and software are brought out by this analogy.
1. Both hardware and
software are necessary for a computer to do useful job. Both are complementary
to each other.
2. The same hardware can be
loaded with different software to make a computer system perform different
types of just as different songs can be played using the same cassette player.
3. Except for upgrades (like increasing
the main memory and hard disk capacities, or adding speakers, modems, etc)
hardware is normally a one-time expense whereas software is a continuing
expense. Just as we buy new cassettes for the newly released songs or for songs
whose cassettes we do not have, similarly one busy new software to be run on
the same hardware as and when need arises or funds become available.
Types
of Software:- A wide variety of computer software is available today. Although the
range of software available is vast and varied, most software can be divided in
to two major categories;
- System software, and
- Application software
These two types of software
along with a few examples of each type are described below.
System Software: - System
software is a set of one or more programs designed to control the operation and
extend the processing capability of a computer system. In general, a computer’s
system software perform one or more of the following functions;
1.supports the
development of other application software.
2.supports the
execution of other application software.
3.monitors the
effective use of various hardware resources such as CPU, memory, peripherals,
etc.
4.communicates
with and controls the operation of peripheral devices such as printer, disk,
tape etc.
Thus system software makes
the operation of a computer system more effective and efficient .it helps the
hardware components work together and provides support for the development and
execution of application soft ware (program). The programs included in a system
software package are called system programs and the programmers who prepare
system software are referred to as system programmers.
System software offers
several advantages and conveniences to application programmers and computer
users in general. Good system software allows application packages to be run on
the computer with less time and effort. Without system software, application
packages could not be run on the computer system. Thus system software is an
indispensable part of a total computer system. A computer without some kind of
system soft ware would be very ineffective and most likely impossible to
operate. The production of system software is a complex task that requires
extensive knowledge and considerable specialized training in computer science.
System programmers are highly trained computer professionals. Because of its
technical complexity, system software are normally developed and distributed by
the computer manufacturers .The customer who buys or leases a computer system
would usually receive, in addition to the hardware, some software needed for
the effective operation of his/her computer.
Some of the most commonly
known types of system software are operation system, programming language
translators, utility programs, Assemblers, Compliers , Interpreter and
performance monitoring software and communication software. They are briefly
described below.
Language
Translators: - Language translators are
system software that transform the instructions prepared by programmers using
convenient programming languages into a from that can be interpreted and executed
by a computer system. Along with every programming language developed, a
language translator was also developed, which accepted the programs written in
a programming language and executed them by transforming them into a form
suitable for execution. Depending on the programming language used, language
translators are divided into three major categories: Assemblers, Compilers and
Interpreter.
Assemblers:- Compared to all the types of programming
languages, assembly language is closest to the machine code. The assembly
language program must be translated into machine code by a separate program
called an assembler. The assembler program recognizes the character strings
that make up the symbolic names of the various machine operations and
substitutes the required machine code for each instruction. In short, an
assembler converts the assembly codes into machine codes, making the assembly
program ready for execution.
Compliers:- A compiler is
a type of language translator that translates a program code into machine
language. The programs written in any programming language needs to be
converted to binary form. Therefore, in order to execute the programs, a
programmer needs to compile the written programs. As a system program, a
compiler translates source code into object code. For examples: Borland C++ compiler and
Microsoft VC++ compiler
Interpreters:- An interpreter
is another type of language translator, which analyses and executes the source
code in line-by-line manner, without looking at the entire program. In other
words, an interpreter translates a statement in a program and executes the
statements immediately, that is, before translating the next source language
statement. The advantage of interpreters is that they can execute a program
suddenly. Compilers requires some time
before an executable program is made because it looks at the whole source code.
However, programs produced by compilers run much faster than the same programs
executed by the interpreter. For examples: GW-BASIC Interpreter and LISP
Interpreter
Operating
Systems;- Every computer has an operating system software that takes care of
the effective and efficient utilization of all the hardware and soft ware
components of the computer system . It is responsible for performing basic
tasks such as recognizing input from the keyboard, sending output to the
display screen, keeping tracks of files and directories on the hard disk, and
controlling peripheral device such as printers and modems. In addition, the
operating system ensures that different programs executing at the same time do
not interfere with each other.
Function of Operating System:- The main
function provided by most operating system of today are as follows:
- Process Management:- A process is a
program in execution. During execution, a process needs certain resources
such as CPU time, memory space, files and I/O devices. At a particular
instance of time, a computer system normally consists of a collection of
processes. The process management module of an operating system takes care
of the creation and deletion of processes, scheduling of various system
resources to the different processes requesting them, and providing
mechanism for synchronization and communication among processes.
- Memory Management:- To execute a
program, it must be loaded, together with the data it accesses, in the
main memory. To improve CPU utilization and to provide better response
time to its users, a computer system normally keeps several programs in
main memory. The memory management module of an operating system takes
care of the allocation and de-allocation of memory space to the various
programs in need of this resource.
- File Management:- All computer systems
are used for storage, retrieval and sharing of information. A computer
normally stores such information in units called files. Processes can read
information from files and can create new files for storing newly generated
information. Information stored in files is made persistent by storing
them on a secondary storage media such as a magnetic disks. The file
management module of an operating system takes care of file-related
activities such as organization, storing, retrieval, naming, sharing and
protection of files.
- Device Management:- A computer system
normally consists of several I/O devices such as terminal, printer, disk
and tape. The device management module of an operating system takes care
of controlling all the computer’s I/O devices. It keeps track of I/O
requests from processes, issues commands to the I/O devices, and ensures
correct data transmission to/from an I.O device. It also provides an
interface between the devices and the rest of the system that is simple
and easy to use.
- Security:- Computer system
often store large amounts of information, some of which is highly
sensitive and valuable to their users. Users can trust the system and rely
on it only if the various resources and information of a computer system
are protected against destruction and unauthorized access.
- Command Interpretation:- A user
communicates with the operating system, for using the various system
resources, via a set of commands provided by the operating system. The
operating system also provides a simple language, known as command
language or job control language(JCL), using which a user can put several
commands together from the commands set to describe the resource requirements
of the job. The command interpretation module of an operating system takes
care of interpreting user commands, supplied individually or in the form
of command language, and directing the system resources to handle the request.
Types of Operating System:- The operating
system has evolved immensely (hugely) from its primitive (ancient) days to the present digital era.
Batch:-This type of
operating system was one of the first to evolve. Batch processing operating
system allowed only one program to run at a time. These kinds of operating system
can still be found on some mainframe computers running batches of jobs. Batch
processing operating system works on a series of programs that are held in a
queue. The operating system is responsible for scheduling the jobs according to
priority and the resources required. For example: this operating system would
be best suited for a company wishing to automate their payrolls. List of
employees will be entered, their monthly salary will be calculated, and
corresponding pay slips would be printed. Batch processing is useful for this
purpose since these procedures are repeated for every employee each month.
Multiprogramming:- Multiprogramming refers to the situation in
which a single CPU divides its time between more than one job. It is term given
to a system that may have several processes in "states of execution"
at the same time. Multiprogramming increases CPU utilization by organizing jobs
when CPU becomes less idle, waiting for input, output or data transfer
operations to be completed. More is the
number of programs competing for resources, better will be resource
utilization. In this manner multiprogramming increases the over all performance
of the system.
Multiprocessing:- Multiprocessing refers to simultaneous execution of two or more
processes by a multiple, processor computer system. Additional processors are
added to the system to enhance
the throughput. The additional processor can be an Input-Output Processor (IOP)
or
a CPU. Generally, multiprocessing system is defined by a system having more
than one CPU.
Programming
Languages:- A computer, being an electronic device, cannot understand
instructions if provided in a general language. Therefore, a special language
is used to provide instructions to a computer system. This language is known as
computer programming language. It consists of a set of symbols and characters,
words and grammar rules that permit the user to construct instructions in the
format that can be understood and acted upon by the computer system. A major
goal of computer scientists is to develop computer system which can accept
instructions in normal human language – known as Natural Language Processor.
Generations of Programming
Languages:-
The term 'generation' of computer languages is used to
categorize the generic enhancements in various computer languages. It shows the
step-by-step evolution of programming languages. Each generation indicates
significant progress towards making computers easier to use. Computer languages
by generation are classified as follows:
First Generation (late 1940s)
e.g. machine language
Second Generation (early 1950s)
e.g. assembly language
Third Generation (late 1950s through 1970s)
e.g. high level language
Fourth Generation (late 1970 onwords)
includes a whole
range of query languages and other tools.
Classification of Programming
Languages
Computer programming languages can be classified into two
major categories:
Low Level
High Level
Low Level Languages
The languages which use only primitive operations of
the computer are known as low level languages. In these languages, programs are
written by means of the memory and registers available on the computer. As we
all know that the architecture of computer differs from one machine to another,
so for each type of computer there is a separate low level programming
language. In the other words, Programs written in one low level language of one
machine can't be ported on any other machine due to architectural changes.
Because of this, low level languages are known as machine dependent languages.
Examples are Machine Language and Assembly Language.
Machine Language:- In machine language programs, the
computation is based on binary numbers. All the instructions including
operations, registers, data and memory locations are given in there binary
equivalent.
The machine
directly understands this language by virtue of its circuitry design so these
programs are directly executable on the computer without any translations This
makes the program execution very fast. Machine languages are also known as
first generation languages. A typical low level instruction consists
essentially of two parts:
u An Operation Part : Specifies
operation to be performed by the
computer,
also known as Opcode.
u An Address Part : Specifies
location of the data on which operation
is
to be performed.
Writing programs
in machine language is a tedious task since it is very difficult
for humans to remember binary codes of all the operations. The number of bits
in
the operation part determines the number of possible unique instructions that
can
be framed for a computer to execute. The number of bits in the address part
determines the number of directly addressable, unique storage locations in
internal memory of the computer.
Advantages
Machine language makes most efficient use of computer system
resources like storage, registers, etc. The instructions of a machine language
program are directly executable so there is no need of translators. Machine
language instructions can be used to manipulate the individual bits in a
computer system with a very high execution speed due to direct manipulation of
memory and registers.
Drawbacks
Machine languages are machine dependent
and, therefore, programs are not portable from one computer to the other.
Programming in machine language usually results in poor programmer
productivity. Machine languages require programmers to control the use of each
register in the computer's Arithmetic Logic Unit and computer storage locations
must be addressed directly, not symbolically. Machine language requires a high
level of programming skill which increases programmer training costs. Programs
written in machine language are more error prone and difficult to debug because
it is very difficult to remember all binary equivalent of register, opcode,
memory locations, etc. Program size is comparatively very big due to non-use of
reusable codes and use of very basic operations to do a complex computation.
Assembly
Language:- Assembly languages
are also known as second generation languages. These languages substitute
alphabetic or numeric symbols for the binary codes of machine language. That
is, we can use mnemonics for all opcodes, registers and for the memory
locations which provide us the more readable form of the program. These
languages also provide us with a facility to write reusable code in the form of
macros. Macros has two parts, one is macro name and the other is macro body
which contains the line of instructions. A macro can be called at any point of
the program by its name to use the instructions given in the macro
repetitively.
These languages
require a translator known as 'Assembler' for translating the program code
written in assembly language to machine language. Because computer can
interpret only the machine code instructions, once the translation is completed
the program can be executed. A typical assembly language instruction consists
of four components:
u A name or label field
u An operation code
(Opcode)
u An operand
u A comment field
(separated by ; (semicolon) from the executable part of the instruction).
A name or label
field is optional. It is used to mark a place in a program to which computer
control can be transferred. An operation code specifies to the control unit
what processing tasks to perform and the operand field identifies the location
of data item in primary memory. The comment field enables a programmer to write
relevant notes and thereby improve the program documentation. This field is
optional. In assembly language, symbols are used rather than absolute
addresses, to represent memory locations, e.g. hexadecimal value can be used to
represent the memory location of the data in a statement. For example, 2AH for
hexadecimal where 2A represents some memory location. Similarly BX and CX can
be used to represent B register and C register of the computer's ALU
respectively. Mnemonics are used for operation code, i.e. short abbreviations
that help programmers remember what the codes represent.
Advantages
Assembly languages provide optimal use of computer resources like
registers and memory because of direct use of these resources within the
programs. Assembly language is easier to use than machine language because
there is no need to remember or calculate the binary equivalents for opcode and
registers. An assembler is useful for detecting programming errors. Assembly
language encourages modular programming which provides the facility of reusable
code, using macro.
Drawbacks
Assembly language programs are not directly executable due to the
need of translation. Also, these languages are machine dependent and,
therefore, not portable from one machine to another. Programming in assembly
language requires a high level of programming skills and knowledge of computer
architecture of the particular machine.
High Level Language:- All high level languages are procedure-oriented languages and are
intended to be machine independent. Programs are written in statements akin to
English language, a great advancement over mnemonics of assembly language. That
is, the high level languages use natural language like structures. These
languages require translators (compilers and interpreters) for translating high
level language programs into machine language programs for execution. The
programs written in a high level
language can be ported on any computer, that is why known they are known
as machine independent. The early high level languages come in third generation
of languages, e.g. COBOL, FORTRAN, PASCAL, BASIC, APL, etc.
These languages enable the programmer to write
instructions using English words and familiar mathematical symbols which makes
it easier for programmers to concentrate on the logic of problem-solving rather
than technical details of the computer. It makes the programs more readable
too. Once coded, programs are easier to understand and modify. However,
procedure-oriented languages still have some disadvantages compared to machine
and assembly languages. (1) Programs execute more slowly. (2) The languages use
computer resources efficiently.
4GL:- Fourth generation languages (4GLs) are a class of
software designed to simplify the task of developing a new application by
making the user interface similar to natural languages. These are very easy to
use languages. Some 4GLs are designed to improve the productivity of
programming professionals while others are designed to be used directly by the
end user.
4GLs are
designed more for specification of what tasks to be accomplished as compared to third generation procedural
languages which focus on how to solve a problem. These languages are developed
for the purpose of making database management more efficient and is also known
as database management systems. Database Management System (DBMS) is a concept
to construct, organize and manipulate a large set of data in a best possible
way.
Example:
u Suppose personal details
of all employees are stored in a file
called Employee Master File. It is required to display all the information
about a particular employee, say, David.
u To accomplish the task
using procedural (third generation) language, the programmer would have to
write a series of instructions as follows:
Step 1 Get a record
from the employee master file.
Step 2 Check if the
record belongs to employee name "David".
Step 3 If the answer
for step 2 is "Yes", display details.
Step 4 Otherwise, go
to step 1.
u In 4GLs the task could be
accomplished by giving a single instruction as follows:
Display
all for employee name =
"David" from employee master file.
Many fourth
generation languages either incorporate a query language or support a standard
query language like SQL, which can be used to interact with the database.
e.g.: SQL
statement for the above illustration will be:
[Select * from employee_master where
emp_name = "David".]
Note * means all the fields
of record.
u Easy to use; little or no
computer knowledge is required.
u Machine independent.
u Enhanced programming
productivity.
u Ease of modification and
maintenance of data.
u Good documentation.
Disadvantages
u 4GL programs are less
efficient from the computer resource utilization point of view.
u Programmers become less
skilled over a period of time.
u Security standards are difficult to enforce in 4GL environment.
Object Oriented Languages:-
Object-orientation
can refer to a set of design principles, a programming style, or features of
programming languages that support that style. Continuing from an
earlier post on the history of programming languages, let’s next concentrate on the purpose and history of the languages
that support OOP.
The purpose
of object orientation is to model, in code, the objects that make up the
application you’re writing and the interactions between them. As in human
language, it’s impossible to describe any process without referring to the
nouns that are involved. All programming languages provide some nouns, but
until object-oriented languages arrived on the scene, the programmer couldn’t
create his/her own nouns very easily. Programming was limited to talking about
the set of nouns provided by a language: numbers, characters, channels, etc. Of
course, programmers built more abstract structures around this limited set of
nouns, but the code that described those abstractions was much more complex
than talking about them in English. Object-oriented languages allow you to
define types of objects (called classes) that are derived from, or composed of,
other types. In addition to this data component, the functions (also called methods)
that “belong” to the data are also grouped in the class. This has at least
three benefits:
- Encapsulation. Functions that are internal to a
class can be marked as “private”. This means that they’re hidden from any
code outside the class, so their implementation can be changed without
bothering any code that uses the class. Conversely, the methods that are
marked “public” form a well-defined interface that should not be
changed without due consideration, because client code relies on it.
- Inheritance. You can derive one class from
another, and the new class automatically contains all of the methods and
data of the original class. This is useful when some subset of your
objects needs an additional capability, but you don’t want to give that
capability to all of the other objects.
- Polymorphism. Polly who? It’s a Greek-derived term
that means “many forms”. In OOP, it means that sending the same message
(in most OO languages, this means calling a method by name) may evoke
different responses depending on type. Polymorphism itself has more than
one form. The first form is when a derived class overrides an inherited
method with its own implementation, so that sending the same message
(calling the same function) on two different objects yields a different
behavior depending on their types. A second type of polymorphism is called
“parametric polymorphism”, which means that a class provides different
implementations for a method depending on the types of parameters passed
to it.
Application Software: - Application software is a set of one or more programs designed to
solve a specific problem or do a specific task. For example an application
software for payroll processing produces pay slips as the major output and an
application software for processing examination results produces mark sheets as
the major output along with some other statistical reports. Similarly a program
written by a scientist to solve his/her particular research problem is also an
application software .the programs included in an application software package
are called application programs and the programmers who prepare application
software are referred to as application programmers.
There are literally millions of
application software available for a wide range of applications ranging from
simple applications such as word processing inventory management preparation of
tax returns ,banking hospital administration ,insurance, publishing, to complex
scientific and engineering applications such as weather forecasting ,space
shuttle launching oil and natural gas exploration ,design of complex structures
like aircrafts, ships bridges, sky rise buildings, etc. With so many
applications available, it is not possible to categorize them all and to cover
them here. Hence just to have a feel of what application soft ware dose, some
of the most only known application
software are briefly described below.
Word Processing Software:-Word processing is a term that describes the use of computers to
create ,edit ,view ,format, store, retrieve and print documents (written
material such as letters, reports, books, etc).A word-processing software is an
application software that enables the user to do all these on a computer system.
We need to create documents is so common is every walk of life ,whether it is
at work ,at school, or at home ,that word-processing soft ware is the most
commonly used application software. Today’s word-processing packages normally
support the following features:
Entering Text--- This
feature allows you to enter text with computer’s keyboard. Every character
typed on keyboard is displayed immediately on computer’s screen. Word wrap
features of word-processing software determines when current line is full, and
text that follows is moved automatically to next line. Hence, only time you
have to press enter key is at the end of a paragraph.
Editing Text--- This feature
allows you to make changes in an already entered document. While editing, you
can use either insert mode or type-over mode. In insert- mode, new characters
typed are inserted in the text at cursor’s position. In type-over mode, new
characters typed, replace the existing characters at cursor’s position. While
editing, you can also delete unwanted text. Few characters or words at cursor
position are deleted normally with use of Delete key(to delete characters to
the right of cursor) or Backspace key(to delete characters to the left of
cursor).
Formatting Page Style----
This feature allows you to define page layout format for a document. Definition
of a page layout format may include things such as:
- Space to be left for left, right, top,
and bottom page margins.
- Default spacing between two lines(such
as single space, double space, 1.5 space, etc.).
- Automatic numbering of pages with page
number style and page number position.
- Automatic placement of header and
footer labels on each page.
- Setting text in multiple columns on a
single page. Multi-column option is used frequently in newsletter and
newspaper printing.
Formatting Text---- This feature allows you to format
portions of text in a document to improve its general appearance and
readability. It normally includes things such as:
- Selection of an appropriate font-----
A font is a complete set of characters with same style and size. A
word-processing package comes with several standard fonts, such as Times,
Helvetica, Palatino, etc. Different fonts may be applied to different
portions of the same document.
- Selection of an appropriate font size-----
Font size is measured in points. A point is 1/72 of an inch, and size
refers to the distance from the top of the tallest character to the bottom
of the character that extends the lowest.
- Selecting an appropriate font style------
Commonly used font styles are italic, bold, and underline. They are
normally used to highlight individual words, phrases, or portions of text
in a document.
- Selecting an appropriate justification-----
Justification is alignment of text on left or right margins or on both
margins. In case of left-justification, beginnings of lines are aligned
with left margin of the page. This style is also known as ragged right
because ends of lines at the right edge end wherever the last word ends.
In case of right-justification, ends of lines are aligned with right
margin of the page. In case of full-justification, all lines are aligned
properly with both left and right margins of the page. In case of
center-justification of a particular line, it is placed at the center of a
line with equal spacing on both its left and right ends.
- Indenting text appropriately wherever
desired---- Indentation is used often at the beginning of a paragraph, or
to set aside some portion of text from the main text in a document, or to
enter text in tabular form. Tab stops are used normally for indentation. Tab
stops are pre-defined typically at every fourth or fifth character, or at
every ½ inch from the left margin of a page layout.
- Creating numbered or bulleted list of items-----
This feature allows descriptive items to be presented as a numbered or bulleted
list for better comprehension and readability. Each item in the list has a
separate number, or bullet or some other symbol attached to its beginning.
Numbers or symbols are inserted automatically by word-processing software
as soon as you press enter key.
Entering Mathematical Symbols:--- Several scientific
and engineering documents often use mathematical symbols. This feature allows
you to enter complex mathematical equations using mathematical symbols.
Spreadsheet Software:-A Spreadsheet software is a numeric data analysis tool that allows you
to create a kind of computerized ledger .A manual ledger is a book having rows
and columns that accountants use for keeping a record of financial transactions
and for preparing financial statements. Accountants use the manual ledger with
pencil, erasure and hand calculator to prepare financial statements. This is a
tedious task and often takes a long time due to several iteration of formula
calculations to come out with an acceptable and satisfactory financial
statement. A spreadsheet software offers considerable ease of performing such
tasks by automating all arithmetic calculations and making it much easier to
change certain numeric values and immediately seeing the effect of these
changes across the worksheet (ledger). With spreadsheet software in place, we
are no longer confined to using pencils, erasers , and hand calculator for
dealing with any task that requires numeric data analysis. Some of key features
of spreadsheet packages are:
Rows and Columns----- A
spreadsheet is organized in a tabular form with rows and columns. Numbers are
used to identify rows, whereas letters are used to identify columns. Single
letters are used to identify the first 26 columns and double letters are used
for subsequent columns( A, B,….,Z; AA, AB,…..,AZ; BA, BB,……,BZ;…..). A large
spreadsheet may have hundreds of rows and columns.
Cells------ The intersection
of a row and a column is called a cell. A
cell is identified by its address, which is a combination of its column letter
and row number(such as F4, C18). Data are stored in cells.
Range of Cells----- Many
spreadsheet operations involve a range of cells instead of a single cell. A
range of cells may involve many cells and entering every individual cell
address for an operation to be performed on them may be cumbersome and time
taking. To take care of this problem, all spreadsheet packages allow use of
following types of cell ranges:
- Row
Range-> It is used to include a set of adjacent cells in the same row.
For example, the range B5..D5 refers to the cells B5,C5 and D5.
- Column
Range-> It is used to include a set of adjacent cells in the same
column. For example, the range C5..C9 refers to the cells C5, C6, C7, C8
and C9.
- Block Range->
It is used to include a set of adjacent cells in a rectangular group of
cells. For example, the range B5..D9 refers to the cells B5, B6, B7, B8,
B9, C5, C6, C7, C8, C9, D5, D6, D7, D8 and D9.
Presentation Graphics:- A graphics
software enables us to use a computer system for creating , editing , viewing ,
storing, retrieving and printing designs, drawings, pictures , graphs and
anything else that can be drawn in the traditional manner.
A type of business software
that enables users to create
highly stylized images for slide shows and reports. The software includes
functions for creating various types of charts and graphs and for inserting text
in a variety of fonts. Most systems
enable you to import data
from a spreadsheet application
to create the charts and graphs.
Features: A presentation program
is supposed to help both: the speaker with an easier access to his ideas and
the participants with visual information which complements the talk. There are
many different types of presentations including professional (work-related),
education, entertainment, and for general communication. Presentation programs
can either supplement or replace the use of older visualaid technology, such as
Pamphlets,
handouts, chalkboards, flip charts, posters, slides and overhead
transparencies. Text, graphics, movies, and other objects are positioned on
individual pages or "slides" or "foils". The
"slide" analogy is a reference to the slide
projector, a device that has become somewhat obsolete
due to the use of presentation software. Slides can be printed, or (more
usually) displayed on-screen and navigated through at the command of the
presenter. Transitions between slides can be animated in a variety of ways, as
can the emergence of elements on a slide itself. Typically a presentation has
many constraints and the most important being the limited time to present
consistent information.
Recently a new presentation
paradigm has emerged: zooming presentation programs such as Presentista and Prezi. Instead of
individual slides these ZUIs
(zoom user interface) are based on one infinite canvas on which all content is
presented. This allows for non-linear presentations, the option to present
richer detail of content, and to give a better overview and understanding of
complex visual messages and relations.
Another recent development which
internet based software such as Presentista,
Prezi, SlideRocket, Office
Web Apps or Google Docs has enabled is collaborative development of
the presentation. Several people can work on the presentation at the same time
revising content or reviewing the changes as they are made by others.
Many presentation programs come
with pre-designed images (clip art) and/or have the ability to import graphic
images. Some tools also have the ability to search and import images from Flickr or Google directly
from the tool. Custom graphics can also be created in other programs such as Adobe
Photoshop or Adobe Illustrator and then exported. The concept
of clip art
originated with the image library that came as a complement with VCN
ExecuVision, beginning in 1983.
With the growth of digital photography and video,
many programs that handle these types of media also include presentation
functions for displaying them in a similar "slide show" format. For
example, Apple's iPhoto
allows groups of digital photos to be displayed in a slide show with options
such as selecting transitions, choosing whether or not the show stops at the
end or continues to loop, and including music to accompany the photos.
Similar to programming extensions for an operating
system or web browser, "add ons" or plugins for presentation programs can be used
to enhance their capabilities. For example, it would be useful to export a
PowerPoint presentation as a Flash animation or PDF document. This would make delivery
through removable media or sharing over the Internet easier. Since PDF files
are designed to be shared regardless of platform and most web browsers already have
the plugin to view Flash files, these formats would allow presentations to be
more widely accessible.
Certain presentation programs
also offer an interactive integrated hardware element designed to engage an
audience (e.g. audience response systems) or facilitate
presentations across different geographical locations (e.g. web
conferencing). Other integrated hardware devices ease the job of a live
presenter such as laser pointers and interactive whiteboards.
Database Managements Software:-This application software is designed to take advantage of the
tremendous capability of computer system in storing organizing and selectively
retrieving large volumes of data efficiently A database is a collection of
related data stored and treated as a unit for information retrieval purposes.
It is important here to note the
difference between data and information. Data is stored in a database whereas
information is retrieved from a database. That is data is input to any data
processing system and information is its output .in other, data is the raw
material for a data processing system and information is the processed data.
A database concept can be
best illustrated with an example. For example , a school’s student database
might contain the name, sex, date of birth, current address, permanent address,
parent’s occupation , marks scored in various subjects in each class already
passed , and current occupation for all the students who are either currently
enrolled or have already graduated from the school similarly ,an individual’s
address database might contain the names , addresses, and telephone numbers of
all his/her friends and business contacts. The data of one student in the
student database or one person in the address database is known as a record.
A database software is a set
of one or more programs that enables users to create a database , maintain it
(add, delete and update its records ), organize its data in desired fashion
(for example, sort its records alphabetically name-wise),and to selectively
retrieve useful information from it (for
example , get the telephone number of the person named kashyap rana from the
address database , or get the names of all currently enrolled students from the
student database whose birthday fall today ).
Database software is widely
used today by both large and small organizations to maintain employee data,
customer data, assets data , accounting data, etc. Even individuals find the
database software very useful for maintaining data such as list of addresses
and telephone numbers of their friends and relatives, list of household goods
and other valuables, list of various types of savings in different banks ,etc
.
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