Railways Computers Science Internet Internet and Its Services

Internet and Its Services

Category : Railways

 

Internet and Its Services

 

The Internet has gained popularity and emerged as an important and efficient means of communication. The idea of introducing the Internet was to allow millions of people to share information and ideas, sound, video clips using their computers across the world. The Internet is a worldwide network of networked computers those are able to exchange information with each other. It consists of thousands of separately administered network of various sizes and types.

 

Internet

Internet stands for International Network, which began in 1950's by Vint Cerf known as the 'Father of Internet. Internet is a 'network of networks' that consists millions of private and public networks of local to global scope. Basically, network is a group of two or more computer systems linked together.

The data move around the Internet is controlled by protocols. Under TCP/IP protocol (Transmission Control Protocol/Internet Protocol), a file is broken into smaller parts by the file server called packets. All computers on the Internet, communicate with one another using TCP/IP, which is a basic protocol of the Internet.

 

History of Internet

In 1969, the University of California at Los Angeles, the University of Utah were connected as the beginning of the ARPANET (Advanced Research Projects Agency Network) using 50 kbits circuits. It was the world's first operational packet switching network. The goal of this project was to connect computers at different universities and U.S. defence.

In mid 80's another federal agency, the National Science Foundation, created a new high capacity network called NSFnet, which was more capable than ARPANET. The only drawback of NSFnet was that it allowed only the academic research on its network and not any kind of private business on it. So, private organisations and people started working to build their own networks, which were later interconnected with ARPANET and NSFnet to form the Internet.

 

Advantages of the Internet

(i) Allows you to easily communicate with other people.

(ii) Global reach enables one to connect anyone on the Internet.

(iii) Publishing documents on the Internet saves paper.

(iv) A valuable resource for companies to advertise and conduct business.

(v) Greater access to information reduces research times.

 

Disadvantages of the Internet

(i) It is a major source of computer viruses.

(ii)Messages sent across the Internet can be easily intercepted and are open to abuse by others.

(iii) Much of the information is not checked and may be incorrect or irrelevant.

(iv) Unsuitable and undesirable material available that sometimes are used by notorious people such as terrorists.

(v) Cyber frauds may take place involving Credit/Debit card numbers and details.

 

Internet Connections

Bandwidth and cost are the two factors that help you in deciding which Internet connection is to use. The speed of Internet access depends on the bandwidth.

Some of the Internet connections available for Internet access are as follows

 

Dial-Up Connection

A Dial-up is a method of connecting to the Internet using an existing telephone. Dial-up connection uses the telephone line to connect to the Internet. The modem connects the computer through the standard phone lines, which serve as the data transfer medium. When a user initiates a dial-up connection, the modem dials a phone number of an Internet Service Provider (ISP) that is designated to receive dial-up calls. The ISP then establishes the connection, which usually takes about ten seconds and is accompanied by several beeping and buzzing sounds.

 

Broadband Connection

The term broadband commonly refers to high speed Internet access that is always on and faster than the traditional dial-up access. It uses a telephone line to connect to the Internet.

Broadband access allows users to connect to the Internet at greater speed than a standard 256 KB modem or dial-up access. Broadband includes several high speed transmission technologies such as follows

(a) Digital Subscriber Line (DSL) DSL is a popular broadband connection. It provides Internet access by transmitting digital data over the wires of a local telephone network. DSL is the most common type of broadband service. It uses the existing copper telephone lines. A special modem is necessary in order to be able to use a DSL service over a standard phone line.

(b) Cable Modem This service enables cable operators to provide broadband using the same co-axial cables that deliver pictures and sound to your TV set. Most cable modems are external devices that have two connections, one to the cable wall outlet and the other to a computer. They provide transmission speed of 1.5 Mbps or more.

(c) Fibre Optic This technology converts electrical signals carrying data to light and sends the light through transparent glass fibres of about the diameter of a human hair. Fibre transmits data at speed far exceeding current DSL or cable modem speeds, typically by tens or even hundreds of Mbps.

(d) Broadband over Power Line (BPL) BPL is the delivery of broadband over the existing low and medium voltage electric power distribution network. BPS speeds are comparable to DSL and cable modem speeds. BPL is good for areas, where there are no other broadband connections, but power infrastructure exists, e.g. rural areas.

 

Wireless Connection

Wireless broadband connects a home or business to the Internet using a radio link between the customer's location and the service provider's facility. Wireless broadband can be mobile or fixed. Unlike DSL and cable, wireless broadband requires neither a modem nor cables and as a result it can be easily established in areas, where it is not feasible to deploy DSL or cable. Some ways to connect the Internet tirelessly are as follows

(a) Wireless Fidelity (Wi-Fi) It is a universal wireless networking technology that utilizes radio frequencies to transfer data. Wi-Fi allows high speed Internet connections without the use of cables or wires. Wi-Fi networks can be use for public Internet access at 'hotspot' such as restaurants, coffee shops, hotels, airports, convention centers and city parks.

(b) Worldwide Interoperability for Microwave Access (WiMAX) It is one of the hottest broadband wireless technologies around today. WiMAX systems are expected to deliver broadband access services to residential and enterprise customers in an economical way.

It is based on wireless MAX technology. WiMAX would operate similar to Wi-Fi but at higher speed, over greater distances and for a greater number of users. WiMAX has the ability to provide service even in areas that are difficult for wired infrastructure to reach and the ability to overcome the physical limitations of traditional wired infrastructure.

(c) Mobile Wireless Broadband Services These services are also becoming available from mobile telephone service providers ai others. These services are generally appropriate for mobile customers and require a special PC card with abuilt-in antenna that plugs into a user's laptop computer. Generally, they provide lower speeds in the range of several hundred kbps.

(d) Satellite Satellites which orbiting the earth provide necessary links for telephone and television service. They can also provide links for broadband. Satellite broadband is another form of wireless broadband and is also useful for serving remote.

 

intranet is a private network for iniernet tools, but available within an organisation, in. large organisation. Intranet allows an easy access to corporate information for employees.

Extranet is a private network that uses the internet Protocol and the public telecommunication system to security share part of a business information.

Integrated Services Digital Network (ISDN) It is a digital telephone service that can transmit voice. data and control information over an existing single telephone line. It was the first high speed alternative to regular analysis phone modems.

 

Interconnecting Protocols

A protocol is a set of rules that govern data communications. A protocol defines what is communicated, how it is communicated and when it is communicated. Generally,. Some of protocols used to communicate via. an Internet are as follows

Transmission Control Protocol/ Internet Protocol

The Internet protocol suits are the set of communication protocols used for the Internet. The details of TCP/IP are as follow

(a) Transmission Control Protocol (TCP) It provides reliable transport service, i.e. it ensures that message sent from sender to receiver are properly routed. It converts messages into a set of packets at the source which are then reassembled back into messages at the destination.

(b) Internet Protocol (IP) It allows different computers to communicate by creating a network of networks. IP handles the dispatch of packets over the network. It maintains the addressing of packets with multiple standards. Each IP packet must contain source and the destination address.

 

File Transfer Protocol (FTP)

FTP can transfer files between any computers that have an Internet connection and also works between computers using totally different operating systems. Some examples of FTP software are FileZilla, Kasablanca, gFTP, konqueror, etc.

HyperText Transfer Protocol (HTTP) HTTP defines how messages are formatted and transmitted and what actions should be taken by the Web servers and browsers in response to various commands.

e.g. when you enter a URL in your browser, this actually sends an HTTP command to the Web server directing it to fetch and transmit the requested Web page. HTTP is called a stateless protocol because each command is executed independently, without any knowledge of the commands that came before it.

 

HyperText Markup Language (HTML)

HTML is used for designing Web pages. A markup language is a set of markup (angular bracket, < >) tags which tells the Web browser how to display a Web page's words and images for the user. Each individual markup code is referred to as an element or tag.

 

Telnet Protocol

Telnet is a program that runs on the computer and connects PC to a server on the network and the protocol used on the Internet or Local Area Network (LAN). Telnet session will started by entering valid username and password.

 

Usenet Protocol

The usenet service allows a group of Internet users to exchange their views/ideas and information on some common topic that is of interest to all the members belonging to that same group.

Several such groups exist on the Internet are called newsgroups. Usenet has no central server or administration.

 

Point-to-Point Protocol (PPP)

PPP is a dial account which puts your computer directly on the Internet. A modem is required for such connection which transmits the data 9600 bits per second.

 

Wireless Application Protocol (WAP) A WAP browser is a commonly used Web browser for small mobile devices such as cell phones.

 

Voice over Internet Protocol (VoIP) It allows delivery of voice communication over IP networks, e.g. IP calls.

 

Terms Related to Internet World Wide Web (WWW)

WWW was introduced on 13th March, 1989. The world wide web is a system of Internet servers that supports hypertext and multimedia to access several Internet protocols on a single interface. The world wide web is often abbreviated as the Web or WWW. The world wide web is a way of exchanging information between computers on the Internet, try to tie them together into a vast collection of interactive multimedia resources (Graphics, Audio, Video, Animation and Text).

 

Web Page

The backbone of the world wide web is made of files, called pages or Web pages, containing information and links to resources - both text and multimedia - throughout the Internet. It is created using HTML. There are basically two main types of static and dynamic. Static Web page are those with content that cannot change after accessing the Web page while dynamic Web page content change every time. The main or first page of a Website is known as home page.

 

Website

A group of Web pages athat follow the same theme and are connected together with hyperlinks is called Website. In other words, "A Website is a collection of digital documents, primarily HTML files, that are linked together and that exist on the Web under the same domain". e.g. http://www.carwale.com is a Website while http://www.carwale.com/new/ is a Web page.

 

Web Browser

It is a software application that is used to locate, retrieve and also display content on the world wide web, including Web pages. Web browsers are programs used to explore the Internet. We can install more than one Web browser on a single computer. The user can navigate through files, folders and Websites with the help of a browser.

There are two types of Web browsers as follows

(a) Text Web Browser A Web browser that displays only text-based information is known as text Web browser, e.g. Lynx, which provides access to the Internet in the text mode only.

(b) Graphical Web Browser A Web browser that supports both text and graphic information is known as graphical Web browser, e.g. Internet Explorer, Firefox Netscape, Safari, Google Chrome and Opera.

Note The first graphical Web browser was NCSA Mosaic.

 

Web Server

It is a computer program that serves requested HTML pages or files. A Web client is the requesting program associated with the user. The Web browser is a client that requests HTML files from Web servers. The server computer will deliver those Web pages to the computers that request them and may also do other processing with the Web pages, such as calculations and entries into databases. Every Web server that is connected to the Internet is given a unique address, i.e. IP address made up of a series of four numbers, e.g. Apache HTTP Server, Internet Information Services, Lightppd, etc.

 

Web Address and URL

A Web address identifies the location of a specific Web page on the Internet, such as http://www.learnyoga.com. On the Web, Web addresses are called URLs. URL stands for Uniform Resource Locator.

It is the Web address for a Website or a Web page. Tim Berners Lee created the first URL m 1991 to allow the publishing of hyperlinks on the world wide web. The URL specifies the Internet address of a file stored on a host computer connected to the Internet, e.g.

 

"http://www.google.corn/services,/index/him"

 

 

http      

Protocol identifier

www     

World Wide Web

google.com

Domain name

/services/    

Directory

index.htm   

Web page

 

Domain Name

Domain is a group of network resources assigned to a group of users. A domain name is a way to identify and locate computers connected to the Internet. A domain name must be unique. It always have two or more parts, separated by period/dot (.).

e.g. google.com, yahoo.corn, etc.

Domains are organised by the type of organisations and by country. A three-letter abbreviation indicating the organisation and usually two-letter abbreviation indicating the country name.

 

Most common domain abbreviations for organisation are as follows

 

info       

Informational organisation

corn       

Commercial

gov      

Government

edu       

Educational

mil        

Military

net       

Network resources

org       

Non-profit organisation

 

Some domain abbreviations for country are as follows

 

in         

India

au         

Australia

fr         

France

nz       

New Zealand

uk       

United Kingdom

 

Domain Name System (DNS)

DNS stores and associates many types of information with domain names, but most importantly it translates domain names (computers host names) to IP addresses. It also lists mail exchange servers accepting E-mail for each domain. DNS is an essential component of contemporary Internet use.

Blogs

A Blog is a Website or Web page in which an individual records opinions, links to other site, on regular basis. Many people compare it with a journal, except it is written online and for everyone to see.

A typical blog combines text, images; and links to other blogs, Web pages and other media related to its topic. Most fclogs, are primarily textual, although some focus on art, photographs, videos, music and audio. In education, blogs can be used as instructional resources. These blogs are referred to as edublogs. The entries of blog is also known as posts.

 

Newsgroups

An area on a computer network especially the Internet, devoted to the discussion of a specified topic is known as Newsgroup. Online discussion group that allows interaction through electronic bulletin board system and chat sessions.

Newsgroups are organised into subject hierarchies, with the first letters of the newsgroup name indicating the major subject category and sub-categories represented by a subtopic name.

 

Search Engine

It is a Website that provides the required data on specific topics. Search engines turn the Web into a powerful tool for finding information on any topic. When you type any term in search bar, then the search engine will look for matching Websites from all over the Web.

Many search engines also have directories or lists of topics that are organised into categories. Browsing these directories, is also a very efficient way to find information on a given topic.

Here are some of the most popular search engines

Google              http://www.google.com

AltaVista           http:/www.altavista.com

Yahoo               http://www.yahoo.com

Hotbot              http://www.hotbot.com

Lycos                http://www.lycos.com

Excite                http://www.excite.com

WebCrawler       http://www.webcrawler.com

 

Services of Internet

An Internet user can access to a wide variety of services such as electronic mail, file transfer, interest group membership, multimedia displays, real-time broadcasting, shopping, etc. Some of the important services provided by the Internet are briefed in the following sections

 

Chatting

It is the online textual or multimedia conversation. It is widely interactive text-based communication process that takes place over the Internet. Chat with people using the Internet is somewhat similar to using the telephone for the same purpose. Chatting, i.e. a virtual means of communication that involves the sending and receiving of messages, share audio and video between users located in any part of the world.

e.g. Skype, Yahoo, Messenger, etc.

 

E-mail (Electronic mail)

E-mail is an electronic version of sending and receiving letter. Electronic mail lets you send and receive messages in electronic form. The person who communicates with you could be any other user on the Internet; someone using the computer system as you or other computer system thousands of miles away.

The E-mail is transmitted between computer systems, which exchange messages or pass them onto other sites according to certain Internet protocols or rules for exchanging E-mail. To use E-mail, a user must have an E-mail address. The E-mail address contains all information required to send or receive a message from anywhere in the world. Storage area for E-mail messages is called mail box.

E-mail address consists of two parts separated by @ symbol - the first part is user name and the second part is host name (domain name). However, spaces are not allowed within the

E-mail address.

e.g. arihantbooks@gmail.com

Here, arihantbooks is a username and gmail.com is a host computer name.

 

Video Conferencing

It is a communication technology that integrates video and audio to connect users anywhere in the world as if they were in the same room.

This term usually refers to communication between three or more users who are in atleast two locations, rather than one-to-one communication and it often includes multiple people at each location. Each user or group of users who are participating in a video conference typically must have a computer, a camera, a microphone, a video screen and a sound system.

 

E-learning

E-learning (Electronic Learning) refers to the electronic mode of delivering learning, training or educational programs to users. It is the mode of acquiring knowledge by means of the Internet and computer based training programs.

 

E-banking

E-banking (Electronic Banking) is defined as the automated delivery of new and traditional banking products and services directly to customers through electronic, interactive communication channels. E-banking is also known as Internet Banking or Online Banking.

E-banking means any user with a personal computer and a browser can get connected to his bank's Website to perform any of the virtual banking functions. All the services that the bank has permitted on the Internet are displayed in menu.

It allows customers to access account specific information and possibly conduct transactions from a remote location such as at home or at the workplace.

 

E-shopping

E-shopping (Electronic Shopping) or online shopping is the process of buying goods and services from merchants who sell on the Internet.

Consumers buy a variety of items from online stores. In fact, people can purchase just about anything from companies that provide their products online.

Books, clothing, household appliances, toys, hardware, software and health insurance are just some of the hundreds of products, consumers can buy from an online store. Some E-shopping site are Naaptol, Flipkart, Yebbi, Homeshop 18, etc.

E-reservation

E-reservation (Electronic Reservation) means making a reservation for a service via Internet. You need not personally go to an office or a counter to book/reserve railways, airways tickets, hotel rooms, tourist packages, etc.

Examples of E-reservation sites are as follows

(a) www.irctc.com

(b) www.makemytrip.com

(c) www.yatra.com

(d) www.bookingsite.com

 

Social Networking

It is the grouping of individuals into specific groups, like small rural communities or a neighbourhood subdivision, if you will.

A social networking service is an online service, platform or site that focuses on facilitating the building of social networks or social relations among people.

The most popular sites are currently Facebook, MySpace and Orkut, etc.

Note Facebook was developed by Mark Zuckerberg.

 

E-commerce

E-commerce (Electronic Commerce) includes sharing business information, maintaining business relationships and conducting business transactions by means of telecommunication networks or process of trading goods over the Internet.

Electronic Data Interchange (EDI) is the electronic transfer of a business transaction between sender or receiver computer.

Note E-trading is the process of trading the goods and items over the Internet.

 

M-commerce

M-commerce (Mobile Commerce) provides the application for buying and selling goods or services through wireless Internet enabled handheld devices. It involves new technologies, services and business models.

Note Mobile commerce was launched in 1997 by Kevin Duffey.

 

Tit-Bits

  • When a search engine returns the links to Web pages corresponding to the keywords entered is called a hit, otherwise called a miss
  • With the Webmail interface E-mails are accessible from anywhere in the world.
  • Rich Text formatting helps the sender (of E-mail) format the contents of his/her E-mail message by applying font, size, bold, italic, etc.
  • Cookie is a small message given to a Web browser by a Web server. It stores information about the user's Web activity.
  • Bookmarks are links to Web pages that make it easily to get back to your favorite places.

Other Topics


You need to login to perform this action.
You will be redirected in 3 sec spinner