Internet and Its Services

What is internet?
Ans: Internet is an interconnection of several thousands of computers of different types belonging to the various networks all over the world.

An information superhighway and has logically compressed the world into a cyber village.

Brief History of Internet

—  In 1960s, the DOD of US started a project of network to share data and information.

—  This network was called ARPA (Advanced Research Projects Agency) –ARPANET

—  ARPANET helped in the development of new protocol called TCP/IP.

—  Goal of this project was to create a large computer network with multiple paths using telephone lines to share resources and exchange data.

—  In mid 1980s, another federal agency NSF joined ARPANET after DOD dropped its funding.

—  Linked five regional areas with supercomputers to provide network facilities.

—  Created new, higher capacity network called NSFnet.

—  Allowed universities and research agencies to link up with its supercomputers.

—  The link between ARPANET, NSFnet and other network was called Internet.

—  Original ARPANET was shut down in 1990 and NSFnet was also discontinued in 1995.

—  After the development of WWW in 1990s, the internet really became popular.

Who controls the Internet?
Ans: Different organization like ISOC (Internet Society), W3C (World Wide Web Consortium), IAB (Internet Architecture Board), IEFT (Internet Engineering Task Force), IRTF (Internet Research Task Force), IESG (Internet Engineering Steering Group) and INIC (Internet Network information Centre) gives directive and guideline for the proper use of internet.

Why is internet called ‘network of networks’?

Ans: The internet is called ‘network of networks’ because all the smaller networks of organizations are linked together into the one giant network called the internet.

Which communication protocol is used by the internet?

Ans: TCP/IP is the communication protocol used by the internet.

List the components required for internet connection.
Ans: The components for internet connect are:
i) A TCP/IP enabled computer with web browser
ii) An account with an ISP
iii) Router / MODEM (necessary if you are using a telephone line to access the Internet)
iv) Connection (Dial-up, DSL, Cable, Satellite, Fiber)

List the services provided by internet.

Ans: The services provided by internet are:
i) WWW (World Wide Web)
ii) E-mail (Electronic mail)
iii) FTP (File Transfer Protocol)
iv) IRC (internet Relay Chat)
v) News Group
vi) Telnet
vii) Internet Telephony
viii) E-commerce

What are the advantages of internet?

              Ans:   The advantages of internet are:

i.                 Internet has an endless knowledge supply which anyone can access that too free of cost.

ii.               Selling and buying has become so easy with the use of internet and it has helped millions to sell and buy their goods online.

iii.             internet has given us E-Mail which is fast, secure and reliable mode of communication.

iv.             It makes easy to transfer the file or information.

What are the disadvantages of internet?

 Ans: The disadvantages of internet are:

i)                Increasing virus threats not only steals your sensitive data but also damages your computer.

ii)              People using too much of internet get disconnected from the real world. 

iii)            Pornography that can get in the hands of young children too easily.

iv)             Addiction to online games affects health leading to obesity and serious health issues.

What is E-mail?
Ans: E-mail (Electronic mail) is one of the most popular services provided by the internet which sends and receives mail through the internet.
It is the method of transferring/transmitting data, text, file, digital photo or audio or video file from one computer to another computer over the internet.

Write down the advantages of E-mail.
Ans: The advantages of email are:
i) It allows to send and receive message across the world at very low cost.
ii) It is very fast compared to postal system.
iii) The image, sound, video and documents can be attached to e-mail message.
iv) Multiple copies of same message can be sent to many people.

Write down the disadvantages of e-mail.
Ans: The disadvantages of e-mail are:
i) Minor mistakes in e-mail address may deliver the mail to wrong address.
ii) Since it passes through a vast electronic network, it may be seized in between.

Write down the names of any four sites which provides e-mail services.

Ans: Names of any four sites that provides e-mail services are:

·       www.yahoomail.com

·       www.hotmail.com

·       www.gmail.com

·       www.outlook.com

What are newsgroups?
Ans: Newsgroups are discussion groups that focus on a particular topic such as politics, health, computer, etc. The interested people on the particular field write the information or articles. Then these articles are posted to the newsgroup so that other people can read them.

What is telnet?
Ans: A telnet is a program that allows a user to log into a remote computer on the internet as a user on that system.

What is File Transfer Protocol (FTP)?
Ans: File Transfer Protocol is the internet tool that allows the user to transfer the file from one computer to another computer. It helps to upload and download the files.

What is IRC?
Ans: Internet Relay Chat is one of the important services provided by the internet which allows the user to communicate with each other in real time.

What is internet telephony?
Ans: It is one of the cheapest and reliable services provided by the internet that allows the user to make telephone communication or voice communication through internet.

What is FAQ?

Ans: FAQ (Frequently Asked Questions) is an online document that possesses series of common questions and answers on a specific topic.

What is E-commerce?
Ans: E-commerce is one of the popular service of internet which helps in buying and selling of goods over the internet. It is doing business online through the internet.

What is video conferencing?
Ans: Video conferencing is an important and interesting service provided by the internet which makes communication using sounds as well as pictures.

What do you mean by online banking?

Ans: Online banking is the practise of making banking transaction using the internet.

What is webpage?
Ans: Webpage is an electronic document written using a computer language which contain information about any person ,organization, etc is called HTML.

What is website?
Ans: Website is a collection of web pages that can be published by an organization or individual. It contains home page and other sub pages.

What is upload?
Ans: Upload refers to copying files or documents or programs or data from the user’s computer to the internet.

What is download?
Ans: Downloading refers to copying files or documents or programs or data from the internet server to the user’s computer.

What is web browser?
Ans: Web browser is a computer program that access web pages and displays them on the user computer. Examples of web browsers are Mozilla firefox, google chrome, internet explorer, opera etc.

What is URL?
Ans: URL is a unique address that provides location of a webpage on the internet.

Example of URL: http://www.abc.com/mainpage/first.html

http: protocol, www.abc.com: server name, mainpage: path, first.html: filename

What is browsing/ surfing?
Ans: Browsing means searching information on the internet.

What is search engine?
Ans: Search engine is the website that allows the user to search the information based on keywords or combination of keywords. They are used to locate specific sites and information. Examples of search engines are google, bing, ask.com, yahoo etc

What is a blog?

Ans: A blog is a time-stamped online journal that appears on a website.

A blog is a frequently updated online personal journal or diary. It is a place to express yourself to the world. A place to share your thoughts and your passions.

Blog is a short form for the word weblog and the two words are used interchangeably

What is Wi-Fi (Wireless Fidelity)?

 Ans: Wi-Fi is the name of a popular wireless networking technology that uses radio waves to provide wireless high-speed Internet and network connections.    

  

                                                                                                                                  

What is ISP?
Ans: An Internet service provider (ISP) is an organization that provides services for accessing and using the Internet.

The ISP of Nepal are Mercantile, World Link, Broadlink, Subisu, Classic Tech etc.

What is ISDN?
Ans: It is a high speed digital communication network evolving from existing telephony Integrated Digital Network (IDN) which provides end to end digital connectivity to support a wide range of services, including voice and non-voice service.

What is intranet?

Ans: An intranet is a private computer network that uses the internet protocol to securely share any part of information of an organization.

What is extranet?

Ans: An extranet is a computer network that allows controlled access from outside for specific business or educational purposes.

What is E-fax?

E-fax is the service of the internet through which a user can send and receive faxes(documents or graphics) directly from a computer to another computer.

What is WWW?

Ans: The World Wide Web (abbreviated WWW or the Web) is an information space where

documents and other web resources are identified by Uniform Resource Locators (URLs),

interlinked by hypertext links, and can be accessed via the Internet 

What is Domain Name System?

Ans:  Domain Name System is an Internet service that translates domain names into IP addresses. 

What is HTTP?

Ans: HTTP is a protocol used by the WWW to establish client and server interactions.

Differentiate between video conference and chatting.

Ans:The differences between video conference and chatting are:

          

Video conference	Chatting
It is a service that provides visual communication of parties around the world.	It is a service used to make communication by reading, ignoring and replying the message.
It requires necessary hardware and software to see and speak to each other.	It uses the browser software without using special chat software.
It communicates sounds as well as pictures.	It communicates only text.

Differentiate between e-mail and e-fax.

Ans:The differences between e-mail and e-fax are:

           

E-mail	E-fax
It is a service of internet that allows sending and receiving mails.	It is a service of internet that allows sendind and receiving faxes directly on computer.
E-mail can be sent using a computer with modem, e-mail program and internet facility.	E-fax can be sent using a computer with modem, e-fax program and internet facility.
It is the soft copy service of the internet.	It is the hard copy service of the internet.

Differentiate between chat and e-mail.

Ans:The differences between chat and e-mail are:

              

Chat	E-mail
It enables us to send and receive instant messages.	It doesn’t enable us to receive and send instant messages.
To use chat services, we should have a chat program like Yahoo Messenger, etc.	To use e-mail service, we should have email program like Microsoft Outlook, Euroda etc.
It can be done only when both sender and receiver are physically present on the line.	It can be done even when the both sender and receiver are not present physically on the line.

                                      

LAN Topology or Network Topology - Bus - Ring - Star

Network topology (LAN topology)The arrangement or connection pattern of computers or nodes and other devices of the network is called network topology.

The three basic topologies are:Bus Topology

Ring Topology

Star Topology

Bus topologyThe network topology in which computers and other devices are arranged in linear format which uses a common backbone or wire to connect all the computers and devices is called bus topology.

The advantages of bus topology are:

It is easy to set up computers and other devices in bus topology, because all the devices are connected through a single wire.

It requires fewer cable media, so it is cheaper than other topologies.

It is easy to add new node to the network.

The disadvantages of disadvantages are:

The whole network system collapses if the cable or backbone is damaged.

The network slows down if additional computers are connected.

The limited length of the cable in a network may restrict to connect the workstation or devices.

Ring topology (Loop topology)

The network topology in which computers are connected in the shape of a circle without any end points is called ring topology. Each workstations contains two neighbours for communication or an input and output connections.

Advantages of ring topology are:

It is easy to set up and reconfigure.

Each computer gets equal opportunity to access the network resources.

Disadvantages of ring topology are:

Failure of any cable or single computer may affect the entire network.

It is difficult to detect the errors in this type of network.

Adding or removing the devices affects the entire network.

Star topology

The network topology in which all computers or other devices are connected through a central device called hub or switch is called star topology.

The advantages of star topology are :It is easy to detect errors in star topology.

It is set up and configure.

Failure of a single computer or cable does not affect the entire network.

The disadvantages of star topology are: It requires more cable in comparison of bus topology so it is costlier.
Failure of central devices (hub or switch) break down the whole system.

Network Architecture - Client / Server Network and Peer to Peer Network

Network Architecture [Models of Computer Network]

The arrangement of the computers on the network which is based on the computing model is called network architecture.

Its types are

Centralized computing network

Client / Server Network

Peer to Peer Network

Centralized computing network

A centralized computing network is a network in which a central host computer performs data processing and storage on behalf of clients.

Client/Server networkClient/ server network is a type of network architecture that consists of at least one server and one or more clients or workstations, where users do their work. 

It provides central security administration and the network administrator is responsible for data security and other resources management of the network.

Peer-to-Peer networkPeer-to-Peer network is a group of computers, which function both as servers and workstations to share data, information and other resources of the network. 

It lacks centralized network administration, where the network administrator needs to manage security on each computer. 

It provides no reliable security and might put data in higher risks.

Network Categories - LAN, MAN, WAN

Network Categories

}LAN (Local Area Network)

}MAN (Metropolitan Area Network)

}WAN (Wide Area Network)

LAN

}It is a network which covers small area i.e. within a room, building, or short distance.

}It is controlled by a single organization.

}It uses private connection media.

}LAN offers bandwidth of 10-100 Mbps.

}E.g.: network in a school, college or cyber café.

MAN

}A MAN is a network of computer is computers which are spread over a metropolitan area such as within a city.

}It is controlled by single or group of organization.

}It uses private or public connection media.

E.g.: interconnection between different branches of banks of same branch, ISP Providing internet services.

WAN

}The network system of connecting two or more computers generally across the wide geographical area is called WAN.

}It is controlled by group of organization.

}It uses public connection media such as telephone lines and wireless technology.

}Eg. Internet

Software components of computer network

The software components of computer network are:

Network operating system

Device drivers

Network protocol

Network Operating System

The group of programs that manages the resources on the network is called the network operating system.

Examples of network operating system are Novell Netware, Microsoft Windows NT, Linux, Unix etc.

ProtocolsProtocols are set of rules that the computers on the network must follow to communicate and to exchange data with each other.

Some examples of protocols are TCP/IP, ARP, HTTP, FTP etc.

Device driver

Device driver is a program that controls the functionality of the hardware device.

Example NIC driver controls the functionality of NIC