INTERNET TOOLS

 

CHAPTER – 5 : INTERNET TOOLS

 

CONCEPT OF NETWORKING

Exchange of information is required in many situations between two users. In such situations, data communications is very much required. Data communication refers to the transmission of data from one computer to another by a data carrier cable that connects two computers.

Computer Network can be defined as an interconnected of autonomous (independent) computers. Normally, these computers are connected through a copper wire. Computer network connection can be of two types.

There are two important computers in a network i.e., Server Computer and Client Computer. Server Computer is the main computer that stores the data of all the clients, shares the files and peripherals with the clients. Client Computer is a subordinate computer connected to the Server Computer. It can access the files and peripherals of Server Computer. There can be more than one client computers.

 

THE USES OF A NETWORK

The computer networks offer many uses to its users. While computer networks provide data sharing, device sharing, flexibility and high reliability in data communication, they do offer very specific benefits to the network users. They are :

1] Simultaneous Access :

Because of networked environment, all users in a company can access the same data at the same time. A central server or simply server maintains the commonly used data which can be shared among several people. If one user modifies the shared data, other users in the network will see the modification when they access it.

2] Shared Peripheral devices :

It is very difficult to provide every user one PC and one printer in a company. Because of the networking of PCs, a single printer can be made as a shared device. All users in that network can share this printer to print their jobs. This reduces the cost and space required to purchase and install several printers.

3] Personal Communication :

Because of computer networks and the Internet which is a network of networks, it is possible for us to have personal communications with any person in the world. The common form of personal communication is achieved through an electronic mail. However, due to many protocols and electronic equipment, we can have teleconference with the remote user. Video conferencing and audio conferencing have made the world very small.

4] Easier to backup :

Data in any business is extremely critical. One should take the back up of such data. Network provides a shared storage device on which the backups of critical data is stored and accessed as and when required.

COMMON TYPES OF NETWORKS 1] LOCAL AREA NETWORKS [LAN]

This is an interconnection of autonomous computers within a single building or a small campus. The range of LANs may vary from 10m to 1.5 km. LANs are small sized networks. In LAN transmission technology, each computer usually contains a network interface device that connects the computer directly to the network medium such as a copper wire or coaxial cable. LANs operate between 10 Mbps and 2 Gbps. Since LAN technology covers short distances, they offer lower delays and make very few errors.

2] WIDE AREA NETWORKS [WAN]

This is a collection of computers that are geographically spread over a wide area. There is no limitation on the distance it spans. A WAN can span over a country or a continent. WANs operate usually at slower speeds. Typical speeds for a WAN range from 2 Mbps to 625 Mbps. They offer a much greater delay between connections. It is due to far distances. This delay is due to sending signals to a satellite orbiting the earth.

 

3] METROPOLITAN AREA NETWORK [MAN]

This is a larger computer network as compared to LANs. It connects multiple corporate LANs together. It is generally called MAN. You might have heard people saying “There is a MAN between a LAN and WAN”. The MANs are high-speed networks for sharing the regional information and resources.

 

DIFFERRENT BETWEEN LAN AND WAN :

LAN		WAN
1	Diameter of not more than a few kilometer	Span entire countries
2	A total rate of at least several mbps	Data rate less than 1 mbps to 10 mpbs
3	Complete ownership by single organization	Owned by multiple organization
4	Very low error rates	Comparatively higher error rates

 

INTERNET

Internet is a network of many computer networks. It connects LANs, WANs and even our own personal computer. It is also called the Information Super Highway. We can access any information from any place at anytime on the Internet. We can download to our PC the research papers, send mails to the friends and relatives, watch a movie, deposit or withdraw money online and sell or buy products and services.

·        The internet is often referred to as the “Information Super Highway”

·        No one owns the Internet, but everyone connected to it owns part of it.

·        It is not governed by any central authority but there are agencies and societies that perform coordinating functions, such as the registration of domain names.

·        In 1988, there were about 1 million people with access to the Internet. Currently, there are more than 500 million Internet connections, divided across almost every country in the world.

·        The web sites produced by institutions, business and private users cover just about every imaginable topic.

·        The Internet was developed in 1969 as a communications network for the US military. Soon, other government agencies, colleges and research companies began using the Internet.

·        Internet telephony is a relatively new technology used to digitize sound and transfer it across the Internet.

·        Video conferencing technology for the World Wide Web had been developed.

In order to avail the facilities of internet, our PCs must be connected to the Internet. Therefore, we have to become the subscriber to the Internet. There are many Internet service providers around the globe. In India, BSNL (Bharatiya Sanchar Nigama Ltd) provides Internet Services. Presently, some private organizations like Satyam Infoway, BPL, Wipro etc., started providing Internet Services. These organizations are called ISPs (Internet Service Providers).

CONNECTING TO THE INTERNET :

To connect your PC to the Internet, the following hardware and software are required.

1.         Modem : It stands for Modulator to Demodulator. It is used to connect the PC to a telephone line.

2.         Telephone Line : To transmit data or message over a wide area.

3.         A PPP (point to point protocol) account with an Internet service provider.

4.         Internet connection software (TCP/IP)

5.         Software for E-mailing, browsing the web and so on. (Internet Explorer)

 

SERVICES OF INTERNET :

1] Net Banking :

Net Banking as replaced the conventional way of banking. Net Banking help us in depositing, withdraw or updating the account with just a click on mouse. We can also get the required information about our Bank Account.

2] Education :

No more requires the student has to go college, register and attend the class. Infact a student can now not only register and attend the classes but also give exams for that particular class using Internet.

3] Employment :

This system with which job sector can register and obtain information for the vacancies with the various companies.

4] Seminar, Discussion :

Participating in a discussion about your favourite TV Show with like minded people across the globe. The Internet community is an open form that no government or restrictions. The citizens of this community are termed as Netizens.

5] Greetings :

Sending and receiving greetings for various occasions across the globe.

6] Searching for Information :

Internet provides search engine websites. These websites allows to search the information using keywords. The popular search engines are

www.google.com, ww.khoj.com, www.yahoo.com etc.,

7] Chatting :

If you like to speak or talk and makes new friends. Then Internet is the best place, with chat program you can talk with a group of people whose geographical location you don’t know.

8] E-Mails :

With E-Mails we can send and receive mail messages. E-Mails can be send globally just by paying local telephone charges.

9] Telnet to Other Computer :

With Telnet program you can connect to another computer and use as if you are sitting at it’s keyboard.

 

INTRANET AND EXTRANETS

Intranet is a scaled-down Internet. It is a corporate specific Internet. That is, each and every company may have its own private Internet to serve the needs of its employees and selected contractors who work within the company. Outsiders cannot access intranet. It connects a set of computers using a standard Internet Protocols such as TCP/IP and HTTP.

Extranet is also a scaled-down Internet. It is a great facility to the employees who can access the resources of their company while they are travelling onsite or working from home. It plays a role of business-to-business Internet which allows a limited, controlled, secure access between a company’s intranet and designated, authenticated users located outside the organization. The employees or business partners who have a valid username and password can access the selected information.

 

DEFINITION OF WEBPAGE

A hypertext document is called a web page. Web pages are just ordinary computer files with a few tags added to tell your computer how to display the contents of the file. A webpage is a page within a website. A website contains few or many of such web pages.

 

MEANING OF HTML

HTML stands for Hypertext Markup Language. HTML is a language used to markup the web contents. That is, it specifies how the contents of the WebPages are displayed on the browser. It stands for hypertext markup language. HTML provides a set of tags (or commands) for marking up the web contents.

 

DEFINITION OF WEBSITE

It is collection of web pages. We can also say that it is a computer system that is set up to distribute documents stored in its database. Websites range in size from as little as one page to a vast number of pages, such as those of search engine’s database or a full text book. The websites are hoisted on the web servers.

 

WEB ADDRESSES (URL)

URL is an acronym for Uniform Resource Locator. The URL specifies the Internet address of a file stored on a host computer connected to the Internet. Every file on the Internet, no matter what its access protocol, has a unique URL. Web browsers use the URL to retrieve the file from the host computer and the specific directory in which it resides. This file is downloaded to the user’s client computer and displayed on the monitor connected to the machine.

URLs are translated into numeric addresses using the Domain Name System (DNS). The DNS is a worldwide system of servers that stores location pointers to websites. The general format of a URL is as follows :

type://address/path/filename

Where,            type	€	type of server where the file is located
address	€	address of the server
path	€	location within the file structure of the server
filename	€	name of the file which has the required contents

 

Example:        http://library.standard.edu/research_help/index.html

Domain Names describe organizational or geographical relativities. It indicates the country where the network connection is in the kind of organization that owns it etc,

 

Following are examples of domain names and their meaning

com – Commercial edu – Educational gov – Government

net – An administrative organization for a network, mil – Non classified Military Networks,

org – Usually private organization and other

There are also domain names for countries

dc – Germany ( Dutch land ) it – Italy

nz – New Zealand in – India

 

WEB BROWSING TOOLS

A web browser or simply browser is a program designed to find the hypertext documents on the web. Once it finds the documents it opens that documents on the computer from which search was made. The browser translates the web files into text, images, sound, video etc., Some of the popular Web browsers are :

·        Internet Explorer(Microsoft)

·        Netscape Navigator

·        Netscape Communicator

·        Lynx

·        Mosaic

·        Hot Java

 

ISP’S IN INDIA AND THEIR RESPONSIBILITIES

In order to avail the facilities of internet, our PCs must be connected to the Internet. Therefore, we have to become the subscriber to the Internet. There are many Internet service providers around the globe. In India, BSNL (Bharatiya Sanchar Nigama Ltd) provides Internet Services. Presently, some private organizations like Satyam Infoway, BPL, Wipro, TATA DOCOMO, Airtel, Idea etc., started providing Internet Services. These organizations are called ISPs (Internet Service Providers).

 

RESPONSIBILITIES OF ISP’s

1)        Provide a reliable and accessible conduit for traffic and services.

2)        Provide authentic and authoritative routing information

3)        Provide authentic and authoritative naming information

4)        Report anonymzed security incident statistics to the public

5)        Educate customers about threats

6)        Inform customers of apparent infections in their infrastructure

7)        Warn other ISPs of imminent danger and help in emergencies

8)        Avoid aiding and abetting criminal activity.

 

             AIL

This is a short form of Electronic Mail. It allows users to compose messages and send them to remote individuals or groups. It also allows users to read the incoming e-mails. It is the most widely used Internet service. It offers a fast and convenient method of transferring messages. Everyone should have a e-mail address to send & receive e-mails.

An E-mail system consists of two subsystems : the user agents and message transfer agents. The user agents allow users to send and receive e-mail. The message transfer agents move the messages from one computer to another over network.

The E-mail system is no longer restricted to exchange only text information it is also used to deliver voice mail, facsimiles and audio-visual images. When you compose an e-mail and send it to the receiver, it will be available to the receiver within a few seconds. So, e-mailing is one of the fastest ways of communication. Every e-mail address has the form:

username@organization_name.typeoforganization Example : shafisardarkpl@gmail.com

Advantages of E-mail :

1)        Low Cost : Email extremely cost-effective way to move information around, the world.

2)        Speed : Electronic mail can be delivered almost as fast as the wire can carry it.

3)        Waste reduction : Email goes a long way toward reducing the wastage of paper in the modern office

4)        Ease of use : It is easy to send an email. You don’t have to retype it, find on envelope, get a stamp then find mail box

5)        Record maintenance : Because all messages are digital files, you can automatically  maintain a record of communications

CHATTING

On the Internet, chatting is talking to other people who are using the Internet at the same time you are. Usually, this "talking" is the exchange of typed-in messages requiring one site as the repository for the messages (or "chat site") and a group of users who take part from anywhere on the Internet. In some cases, a private chat can be arranged between two parties who meet initially in a group chat. Chats can be ongoing or scheduled for a particular time and duration. Most chats are focused on a particular topic of interest and some involve guest experts or famous people who "talk" to anyone joining the chat. A chat can also be conducted using sound or sound and video.

VIDEO CONFERENCING

A videoconference is a live connection between people in separate locations for the purpose of communication, usually involving audio and often text as well as video. At its simplest, videoconferencing provides transmission of static images and text between two locations. At its most sophisticated, it provides transmission of full-motion video images and high-quality audio between multiple locations.

A videoconference can be thought of as a phone call with pictures - Microsoft refers to that aspect of its NetMeeting package as a "web phone" - and indications suggest that videoconferencing will someday become the primary mode of distance communication.

SEARCH ENGINE

This is a program that locates information in its database. A search engine functions as a service that searches for information on the Internet. It responds by matching your query terms to the search engine’s index terms in its database, ranking the matches and returning the hits to you. You can type your search keyword and submit for searching. Within a few seconds you will find lots of related pages displayed on the screen. If you do not find the exact match you can search further and so on till you get what you want. Some of the popular search engines are listed below.

·        Alta Vista

·        Dogpile

·        Excite

·        Fast

·        Google

·        HotBot

·        Infoseek

UPLOADING AND DOWNLOADING FILES

·        Look Smart

·        Savvy Search

·        Yahoo

·        Snap

·        WebCrawler

·        Khoj

The process of copying a webpage onto a web server is called publishing the page. It is also called Uploading Files.

The reverse process of copying a webpage from the web server to your local disk is called Downloading Files.