Let us know about Internet
Internet is the short form of internetwork. Internetwork is the result of interconnecting computer networks which may be having different operating system and may be of different make.The internet is also known as Net.
The internet is the common language where dissimilar computers communicate using a set of protocols.
A protocol is a set of rules which the computer use to communicate with each other over a network.
To access the internet on desktop computers one should have:
1.An internet access account from ISP
Internet Service Providers are example Vodafone, Airtel,Aircel,Idea.
Internet addressing scheme assigns numbers and names to identify computers on internet. The names are called as domain names and numbers IP addresses. Every computer on internet is provided by both domain name and IP address. It has both.
http://www.microsoft.com/IE is translated into numeric IP address 18.104.22.168
Internet address can be compared to phone number. Like for every phone number the combination of country code, area code & phone number is unique similarly every computer on internet is identified by unique IP address.
The format of IP address is xxx.xxx.xxx.xxx
Here each xxx is number from 0 to 255.
Like vsnl server at Delhi has IP address 22.214.171.124 where leftmost octet '202' depicts largest network and rightmost octet '1' actual network.
2 letter abbreviation is used for every country in the world.
World Wide Web
World Wide Web is Internet service, based on common protocols which allows a type of configured computer to distribute document in a standardized manner.This Web standard allows programs on different computer platforms as Linux, Windows,Unix to display and format information server.These programs are known as Web browsers.Web browsers are used to format and retrieve HTML documents. LAN is a network for short distances.
The World Wide Web is a collection of million files stored on many computers all over world. These files may be picture, sound,video,text.
How www work?
WWW is based on client server technology. The internet user using web browser software requests document on Web.The browser requests internet host that has the document. The internet host serves information, thus known as server.Hyper Text Transport Protocol is used in this exchange.
Uniform Resource Locator (URL)
Technique that is used to address documents on Web is known as Uniform Resource Locator (URL).
URL is written as-
<protocol>://<web server name>/<file name>
Collection of web pages is known as website. The document on website which can have image, multimedia, text is known as web page. Websites have home pages.It is the front page.
A webpage is a document that is available on World Wide Web.It is an HTML document that has a URL and is stored on a Web Server.It can be longer than one screen on computer. HTML tags are used to create a Web page. Because of these HTML codes text can be made bold,italics,underlined.Paragraphs and numbered bullets can be made.
Web pages are created for number of reasons:
Web is an inexpensive way of advertising for business. We can interact and communicate with customers through it.URL of businesses can be printed on business cards.
Webpage can act as medium to offer information about group,such as school,neighbourhood, church. Meeting schedules can be fixed by it.Announcements can be made and new recruitments can be done by it.
We can create a webpage on our hobbies and put it on world wide web.People with similar hobbies will visit your page,send you email, also help you in searching more information on your hobby.
Pictures of house, resume, sample of work,picture of car can be put on webpage.
Dynamic HTML is a combination of HTML,scripts, stylesheets that make animated documents.
Extended Markup Language:
XML is not only extensible version of HTML, it is a specification for designing markup language. XML is meta language.
Email is a very good means of communication.
Email is an instantaneous mean of communication.
Email is more casual than a memo or letter.Email is the beginning of the forray into internet.
In business communication, email is fast replacing fax and phone.
Advantages of email:
1.Email is cost effective.
2.Email is instantaneous.
3.Email can be reused.
Limitations of email:
1.There is less privacy or security by email.
2.Email is addictive.
We can converse by websites to other web users.This is called as chat.
There are two main categories of chat:
2.Graphics and animation
In textual we write text,it appears on screen of people around world.
In graphics we can send animations and graphics.
Video conferencing and Voice conferencing
Video conferencing is sending images and voice to one or more people by camera and microphone attached to computer and getting back image and voice back.Voice conference is talking by microphone and speaker to another person connected to computer. By video and voice conference we can see faces of people we are talking to as compared to chat rooms.
Ecommerce is used by large businesses to conduct their transactions. Banks have been using electronic fund transfer dedicated networks.
Ecommerce is buying and selling of products and services over internet. Information can also be bought and sold over internet.
Finding information on internet
Information can be found on internet by some programs that are:
WAIS(Wide Area Information Server)