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185102FUNDAMENTALS OF COMPUTING & PROGRAMMING
UNIT II
COMPUTER SOFTWARE
Computer Software Types of Software Software Development Steps Internet Evolution -
Basic Internet Terminology Getting connected to Internet Applications.
Software:
Software is basically the set of instructions grouped into programs that make the
computer to function in the desired way.
It is a collection of programs which is responsible for controlling, integrating and
managing the hardware components of a computer and to accomplish a specific task.
Hardware:
The term Hardware is applied to any of the physical equipments in the computer system,
such as the machinery and equipments of itself usually containing electronic components
and performing some kinds of functions in the information processing.
Difference between Software and Hardware:
S.No Software Hardware
1. It is a collection of program to bring
the computer hardware system into
operation.
It is the physical components of the
computer system.
2. It consists of numbers, alphabets,
alphanumeric symbols, identifies
keywords etc.
It consists of electronic components like
ICs, diodes, resistors, crystals, boards,
insulators etc.3. This should be prepared according to
the type of the software.
The design can be modified according to the
capacity.
4. It will vary as per the computer and its
built-in function and programming
language.
It is almost construct for all types of
computer system.
5. It is designed and developed by a
experienced programmer in a high
level language, which is readable by
the human being.
The hardware can understand only low-level
language or machine language.
6. It is represented in any high levellanguage such as BASIC, COBOL, C,
C++etc
The hardware works only on binary code as1s and 0s.
7. The Software is categorized as
operating systems, utilities, language
processor, application softwares etc.
The hardware consists of Input, Output,
Memory, ALU, Control unit etc.
Types of Software:
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Software can be classified into two categories. They are: System Software and
Application software.
. System Software:
It is a set of programs to help the user to run the computer systems.
It is more transparent and less noticed by the user since they interact with the hardware or
the applications.
Some examples of system software are: operating systems, device drivers, language
translators and system utilities.
Operating System:
Operating System is the first layer of software loaded into main memory when it starts
up.
It acts as an interface between user and the hardware.
Some of the functionalities of the operating system are: memory management, device
management, CPU management etc.
Device Drivers: They are system software which is responsible for proper functioning of devices.
Whenever a device is connected to the computer system, the driver software has to be
installed so that the device can function properly.
A driver acts as a translator between device and the operating system.
Language Translators:
Computers can understand only binary language i.e. codes which consist of 0s and 1s.
The users write instructions in high level language. The translators convert the high level
instructions into machine code.
There are 3 different types of language translators. They are: Compiler: The compiler translates the source code (high level
language code) into object code (Binary form).
Interpreter: An interpreter does the translation and executes the
program line by line.
Assembler: It translates the program written in assembly level
language into machine code.
COMPILERS AND INTERPRETERS
S.No COMPILERS INTERPRETERS
1. It converts all the source code
into machine code
It also converts all the source code into
machine code
2. Compiler executes entire
program at a time
Interpreter translates and then executes each
line of the program, one line at a time
3. The compiler code runs faster The interpreter code runs slower than
compiled code
System Utility:
System utility programs perform day-to-day tasks related to the maintenance of thecomputer system.
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They are used to support, enhance and secure existing programs and data in the
computer system.
ii. Application Software:
This is the most used software by the users.
It is used to accomplish specific tasks.
Application software consists of a single program (Ex. Notepad) or acollection of programs (Ex. Microsoft Office Suite).
Some of the most commonly used application software are:
(i)Word Processors:
A word processor is software used to compose, format, edit and print electronic
documents.
Ex. Microsoft word.
(ii)Spreadsheets:
A spreadsheet application is a rectangular grid, which allows text, numbers andcomplex functions to be entered into a matrix of thousands of individual cells.
Ex. Microsoft Excel.
(iii)Image Editors:
Image editor programs and designed specifically for capturing, creating, editing
and manipulating images.
The programs provide a variety of special features for creating and altering
images. Ex. Adobe Photoshop.
(iv)Database Management Systems:
Database Management software is a collection of computer programs thatallow storage, modification and extraction of information from a database in an
efficient manner.
It controls the security and integrity of the database from unauthorized access.
Ex. Oracle.
(v)Presentation Applications:
A Presentation is a means of assessment, which requires presentation providers
to present their work orally in the presence of an audience.
It combines both visual and verbal elements. Presentation software allows the
user to create presentations by producing slides for the presentation of projects.Ex. Microsoft PowerPoint.
(vi)Desktop Publishing Software:
The desktop publishing is a technique of using a personal computer to design
images and pages, and assemble type and graphics, then using a printer to output
the assembled pages onto paper.
This software is used for creating magazines, books etc. Ex. Adobe PageMaker.
SOFTWARE TERMINOLOGIES:
Some of the common terms used in the field of software are discussed below:
1. Public Domain Software:
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It refers to any program that is not copyrighted. This software is free and can be
used by anyone without restrictions.
2. Freeware:
It is a copyrighted software but given away free by the developers of the
software.
The users do not have the right to modify the content of the software. There
are different types of software. They are:
i. Donationware: The authors of donationware ask that anyone using
their software make a donation to the authors or to some third party
such as charity.
ii. Postcardware: The users of the software have to send the software
provider a postcard as a form of payment.
iii. Abadonware: It is commercial software that has not been sold for a
long time or whose copyright holder is defunct; it has been
abandoned.
iv. Adware: It is distributed as freeware, but it requires the user to viewadvertisements to use the software. It is also called as spyware.
3. Shareware:
Shareware is software which comes with permission for people to redistribute
copies for a limited period.
Anyone who continues to use a copy is required to pay a license fee. The free use
of the software is usually limited to a period.
4. Commercial Software:
Commercial software represents the software purchased from software
publishers.
This software comes pre-packaged, is available in software stores, and can be
obtained through internet.
5. Open Source Software:
It is created by generous programmers and released into the public domain for
public use.
The Source code is available to the users who can make modifications as per the
needs.
The software is distributed under an open source license General Public
License (GPL).
6. Proprietary Software:
It is owned exclusively by a single company or user. They guard knowledge
about the technology or the products internal working.
It is also called as closed source software. Example. Microsoft Windows
operating system.
7. Firmware:
It is a combination of software, permanently stored in the memory.
It is a program or data that has been written onto ready only memory. Example.
BIOS.
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Installing and Uninstalling Software:
Software which is purchased or acquired has to be installed on the computer so that it
can be executed.
During the installation process, files are copied to their appropriate locations and icons
are added to the system menus.
Definition: The process of copying software from CD-ROM to the hard disk and
configuring it to work with the computer hardware is knows as the software
installation.
A special program known as installer does the installation process. The installer
decompresses the required files within it, and places them in proper folders.
Installation files usually have the extension .EXE or .ZIP. If the installation is of .EXE
extension (ex. Setup.exe), double click the file and follow the instructions after that to
install the software. If the installation is of .ZIP extension, the user has to decompress
the compressed file and then install the software.
Software Upgrade: It is a process by which a newer version of the existing software is
installed.
Software Update: It is a new release of software that is an error correction release and
does not contain new functionality.
Software Patch: It is a collection of one or more files that corrects flaws in the
performance, reliability or security of a specific software product.
Uninstall program completely removes all files of that program and all associated files
in other directories. Properly uninstalling a program means deleting all the files and
undoing any changes made to system files fully.
Software Piracy:
It is the unauthorized copying of an organizations internally developed
software or the illegal duplication of commercially available software.
While purchasing software, the user gets a license to use the application but it
cannot be copied on other machines.
A software license is a type of proprietary license, which acts as a
memorandum of contract between the producer and user. It is also called as End User
License Agreement (EULA).
Starting a computer ( Booting)A Fundamental operation in computer is the booting process. This process is performed
through a series of steps. They are:
1) The Computer is switch ON.
2) Computer loads data from ROM and checks whether all the major components like
processor and hard disk are functioning properly.
3) Computer loads BIOS (Basic Input/Output System) from ROM to determine the
machines fundamental configuration and environment. The information stored in
ROM BIOS chip determines what peripherals the system can support.
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4) Computer loads the operating system from the secondary storage (hard disk) into RAM.
This allows the CPU to have immediate access to the operating system, which enhances
the performance and functionality of the overall system.
There are two types of Booting process. They are:
1. Warm Booting: Restarting the system by pressing the restart button or pressing
Ctr+Alt+Del.
2.Cold Booting: Starting the computer by giving power supply and pressing the start
button.
SOFTWARE DEVELOPMENT STEPS:
The software development process passes through different phases, before a useable
application emerges, thus there are secured way to progress through these phases, and each
way is also called a software process. The phases of the software development steps are
considered as the system development life cycle.
The phases of software development steps
a) Requirement Analysisb) Design
c) Development
d) Testing
e) Implementation and Maintenance
Requirement Analysis
The objective of the requirement analysis is to identify and document the user
requirements for the proposed system.
It is also the process of understanding what is needed or wanted, and expressing the
result in writing. This is the first and the most important step in the software development.
Design
Development
Testing
Implementation &
Maintenance
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Requirement Analysis
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The main objective of the requirement analysis is to produce a document that properly
specifies all requirements of the customer. That is called software requirement
specification (SRS) document.
Analysis is the process of understanding what is needed or wanted, and expressing the
result in writing.
Design Process
The design phase is the process of designing exactly how the specifications are to be
implemented.
It defines specifically how the software is to be written including an object model with
properties and method.
Design phase could very expansive to solve in the later stage of the software
development, so much care is taken during this phase.
Development or coding
The design must be translated into a machine readable form. The coding or
development step performs this task.
The development phase involves the actual coding of the entire application.
Programming tools like compiler, interpreter, Debugger are used to generate the code.
Different High level languages like C, C++, java COBOL etc. are used for writing
programs.
Depending upon the application, the right programming language is chosen.
Testing
Testing is the process of executing software with sample or test data put into regular
use.
Different testing methodologies are used for correcting the error. Different testing tools
available for detect error and correct the error.
Implementation and maintenance
This involves installation and initial training and may involve hardware and network
upgrades.
Software will definitely undergo changes once it is delivered to the customer.
Changes could happen because of some unexpected input values into the system.
Changes in the system could directly affect the software operation
The maintenance phase of the project is the last component and it continues as long as
warranty, extended warranty or support contract is in place.
The phases of the Software Development Steps
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a. Requirement AnalysisSpecifying what the applications must do?
b. Design
Specifying, what the parts will be, and how will they fit
together?
c. Developing
Writing Code
d. Testing
Executing the application with test data
e. Implementation & Maintenance
Repairing defects and adding capability
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S.
No
Stage Key Questions Results
1. Requirement Analysis:
Preliminary Survey, Initial
Investigation
What is the Problem? Statement of Scope &
Objectives.
Performance Criteria
Feasibility Study: Evaluation
of existing System &
Procedures
What are the Users needs?
Is the problem worth
solving?
Technical, Cost Benefit
Analysis.
Analysis: Detailed Evaluation What must be done to solve
the problem?
Logical model of the
system.
2. Design: General design
specification, detailed design
specification
How the problem to be
solved?
What is the processing flow?
Hardware specifications,
Cost estimates.
3. Development: Writing Source
code for the modules designed
What is the actual operation? Source code written for
every module.
Documentation of the
operation of the system.
4. Testing: Unit Testing,
Combined Module testing
Is the output correct? Formal System tests
5. Implementaion &
Maintenance: Evaluation
maintenance, Enhancement
Is the system running at the
customers end?
Should the system bemodified?
User requirements met.
User standards met.
INTERNET
The internet is a worldwide, publicly accessible network of interconnected computer
networks that transmit data using the standard Internet Protocol (IP). It is a network of
networks.
Evolution of Internet:
During 1960s, US department of defence conducted an experiment where the computers were
interconnected and they could still work even after a disaster like nuclear war.
The network was called ARPANET (Advanced Research Project Agency
Network).This experiment was the forerunner of todays Internet.
During 1970s, ARPA (Advanced Research Projects Agency) helped in the
development of a new protocol knows as TCP/IP for transferring data between
networks.
In the 1980s, Usenet newsgroups and Electronic mail came into picture. Internet
became popular in the 1990s after the development of the World Wide Web (WWW).
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WWW permits access to information using a Graphical User Interface (GUI) and the
use of hypertext links to access information across the network.
The Internet today is a repository of every consumable type of information.
Basic Internet Terms:
Web page: The World Wide Web consists of files, called pages or web pages which
contain information and links to resources throughout the Internet.
A web page is an electronic document written in a computer language called HTML.
These web pages are linked together by hyper links. The web pages are also knows as
HTML documents.
Website: A website is a set of related web pages published by an organization or an
individual.
Home page: A home page is a starting point or a doorway to the website. Home page
provides an overview of what could be found at the website.
Browser: A browser is a computer program that accesses web pages and displays them
on the computer screen. Browser is needed to access the World Wide Web.
Uniform Resource Locator (URL): Each web page has a unique address, called a URL
that identifies the location of that page on the internet. The format of the URL consists of
six parts: protocol, WWW, domain name, domain type, path and file name.
Example:
http://www.google.com
Hypertext: It refers to the text or image that connects to other documents. It is also
called as hypertext link, hotlink or link.
A hyper link is used to jump to another part of the same page or to load adifferent web page.
Hyperlinks are the foundation of the web and the operation of the web relies
primarily on them as it is a means of information retrieval. Producing hypertext for the
web is accomplished by creating documents with HTML (Hyper Text Markup
Language).
Internet Service Provider: An ISP is a company that provides access to the internet to
individual or companies.
The ISP provides the user software package, username, password and
access phone number. Equipped with a modem, the user can then log on to the Internet and
browse the web.
Web Server: A server is a computer equipped with server software, which provides a
specific kind of service to client software running on other computers.
A web server is a computer that answers requests from users
computers. It serves images and static content, such as web pages to fill the clients
requests
To view a website, the browser sends a request to the server.
On receiving the request, the server sends the appropriate web page tothe clients machine.
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The clients machines receive the information in the form of HTML
commands.
The browser interprets the HTML, finds all the pictures and displays the
information onto the users screens.
1 2
Browser reads the text sent by the server & web page is displayed on clients
screen
1. Browser requests for information.
2. Server searches for the information and send it
to the browser.
Download & Upload: Download refers to the
activity of moving or copying a document, program or other data from the internet or other
interconnected computers to ones own computers.
Upload refers to the activity of users moving or copying a document, program or other data
from their computers to the Internet.
Online & Offline: Online is referred to as connected to the World Wide Web via Internet.
Offline is referred to the actions performed when the user is not connected, via
telecommunications, to another computer or a network like the internet.
GETTING CONNECTED TO INTERNET:
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The basic requirements for getting internet connections are:
A TCP/IP enabled computer with a web browser.
An account with ISP.
A telephone line plugged to a suitable socket.
A modem to connect the computer to the telephone line.
TYPES OF INTERNET CONNECTION:
There are six different types of Internet Connection available. They are:
Dial-up: A dial-up connection is the access method that uses telephone lines to
connect to the Internet.
It is the most common way that individuals who use home computers connect to
the Internet.
To connect to the Internet by using dialup, the user needs to specify a user name,
a password and a telephone number. After the connection is established, the user can start browsing sites on the
Internet.
ISDN: It stands for Integrated Services Digital Network.
It is used in business and commercial use.
ISDN involves the digitization of telephone network so that voice, graphics, text
and other data can be provided to users from a single terminal over existing
telephone wiring.
Cable Modem: A cable modem connects the user to the Internet through a cable
television line. A cable modem will typically have two connections, one to the television outlet
and the other to the computer.
Cable modems not only provide a faster internet access but they also give added
interactivity to the television.
Leased Line:
This facility provides reliable, high speed internet access.
A leased line connection is an affordable way to line two or more sites for fixed
monthly charges.
Leased line facility can be provided via fibre optic or copper lines. It provides a consistent amount of bandwidth and is an excellent way to provide
data, voice and video links between sites.
DSL:
Digital subscriber line is provided through existing phone line, but it works
differently than regular analog modem dial up access.
It operates over normal telephone lines and it can be used simultaneously with
the telephone.
Broadband:
This type of access is good for remote locations, where ISDN, cable or DSL arenot available.
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Satellite connection can be either a two-way service or a one-way service.
In case of two-way satellite service, the data is transmitted via satellite to a dish
antenna at the users house.
In a one-way system, the user needs a conventional modem and telephone link to
an ISP.
INTERNET SERVICES
The internet has become the biggest domain of information. An Internet user has
access to a wide variety of services such as e-mail, WWW etc. Some of the important Internet
services are given below:
World Wide Web: The World Wide Web is one of the most popular services available on
internet.
It is a subset if the Internet and it presents text, images, animation, video, sound
and other multimedia in a single interface.
The web is a part of the internet and it refers to a system of Internet servers that
supports hypertext using a specific internet protocol called HTTP (Hyper Text
Transfer Protocol) on a single interface.
INTERNET
Internet Telephony &
Video Conferencing
News Groups
Mailing List
File Transfer Protocol
Telnet
IRC, Chatting & Internet
Messaging
E-Commerce
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Electronic Mail (E-Mail): E-Mail is a fast, easy and inexpensive way to communicate with
other Internet users around the world.
Each user of e-mail has a mailbox address to which messages are sent and the
mailbox can be accessed from anywhere and at anytime.
E-mail can also be used to send documents, images, audio, video etc. as an
attachment along with the mail.
File Transfer Protocol (FTP): FTP or File Transfer Protocol is a set of rules that enables a
user to log on to another computer and transfer information between it and his/her computer.
FTP allows the users to get access to the files stored in the directory of a remote
computer that is connected to the Internet.
FTP sites can consist of hundred to thousands of files with information on books,
music, software, images etc.
Telnet: The word Telnet is derived from telecommunications and network and is a protocol
that allows a user to long on to a remote computer.
Once connected, the users computer emulates the remote computer. When the
user types in commands, they are executed on the remote computer.
The users computer, which initiates the connection, is referred to as the local
computer or telnet client, and the machine being connected to, which accepts the
connection is referred to as the remote computer or telnet server.
OS TCP/IP
Telnet Server
TCP/IP OS
Telnet Server
Client
MachineINTERNET
1
2
3
Reading the servers information
Request to Server
Request Received from client
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Internet Relay Chat (IRC): IRC is a service on the internet that allows people to
communicate in real-time and carry on conversations via the computer with one or more
people.
It provides the user with the facility to engage in simultaneous online conversations
with other users from anywhere in the world.
The user runs a program to connect to an IRC server.
The server relays information to and from other servers on the same net.
Chatting and Instant Messaging: Chat programs allow users on the Internet to communicate
with each other by typing in real time.
The Users log into chat rooms to exchange comments and information about the topics
addressed on the site.
Internet Telephony: Internet telephony is the use of Internet rather than traditional telephone
company infrastructure to exchange spoken or other telephonic information.
It consists of hardware and software that enable people to use the Internet as a
transmission medium for telephone calls.
Video Conferencing: Video conferencing enables face-to-face communication across
networks.
A Video conferencing system has two or more parties in different locations, which
have the ability to communicate using a combination of video, audio and data.
The following five elements are needed for video conferencing:
i. Camera
ii. Visual Displayiii. Audio System
iv. Compression of Data both audio and video
v. User Interface and control system
Commerce through Internet: Today, business is taking place through electronic
telecommunication media.
Various organizations offer the facility of shopping online.
This type of business model is known as electronic commerce or E-Commerce.
E-Commerce refers to buying and selling goods and services online.
It is end-to-end digital exchange of information needed to conduct business includingElectronic Data Interchange (EDI) and Electronic Funds Transfer (EFT).
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Newsgroups (Usenet): Newsgroups are international discussion groups that focus on a
particular topic and help in gathering information about that topic.
The topics discussed here cover all the fields such as politics, computers, technology
etc.
The information or articles that make up the news are written by people interested in
a specific topic.
Newsgroups provide a source of information and a medium through which users can
ask questions from the Internet community.
Mailing Lists (List server): The Internet is home to a large community of individuals who
carry out active discussions organized around topic-oriented forums that are distributed via e-
mail.
This method of internet communication is known as mailing list and it enables people with
similar interests from all over the world to communicated and share information with each
other.
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