Development of Internet
Internet is a network connecting many computer networks and based on a common addressing system and communications protocol.
- It was J.C.R. Licklider of the Massachusetts of Technology, who first proposed a global network of computers in 1962, and moved to the Defense Advanced Research Projects Agency (DARPA) to develop it.
- Leonard Kleinrock developed the theory of packet switching, the basis of Internet connections.
- On September 2, 1969, Stephen Crocker and Vinton Cerf, two graduate students at the University of California Los Angeles (UCLA), linked two large computers using a 15-foot cable and tested a new way to exchange data.
- In January, three other “nodes” were added to this network.
- The earliest idea of a computer network intended to allow general communication between users of various computers was the ARPANET, the world’s first packet switching network. It was in December 1969 that ARPA (Advanced Research Projects Agency) went online connecting four major U.S. universities. Designed for research, education, and government organizations, it provides a communications network linking the country in the event that a military attack destroys conventional communications systems.
- In 1972, E-mail was introduced by Ray Tomlinson, a programmer at Bolt, Beranek and Newman, an engineering company in Cambridge, Massachusetts. He used the @ to distinguish between the sender’s name and network name in the email address.
Why the symbol @ used in e-mail is addresses?
An e-mail address identifies a location to which e-mail messages can be delivered. Ray Tomlinson needed a way to separate, in the email address, the name of the user from the machine the user was on. He wanted a character that would not, under any conceivable circumstances, be found in the user’s name. He looked down at the keyboard and chose the @ sign among various punctuation marks available on his Model 33 teletype keyboard, without an idea that he was creating an icon for the internet world. A general format for an e-mail address is: [email protected]_name. The part before the @ sign is the local part of the address, the user name of the recipient, and the part after the @ sign is the domain part which is a host computer name.
The `@’ symbol indicates that the user can be reached on the Internet by giving the email address(also called the User’s Uniform Resource Locator (URL)).
- In 1973, the Transmission Control Protocol/Internet Protocol (TCP/IP) was designed and in 1983 it became the standard for communicating between computers over the Internet. In 1976, US Presidential candidate Jimmy Carter and running mate Walter Mondale used email to plan campaign events. In the same year, Queen Elizabeth sent her first email, becoming the first state leader to do so. In 1982, the term “Internet” was used for the first time.
Files on Internet
The internet is a collection of a large number of client-server based systems. So all files and other resources on it are stored on secondary storage devices of the respective servers. Servers of websites are termed as web servers. When we type in a URL of a website in the address bar of browser, it makes a connection to that web server which in turn fetches the data from the secondary storage device (such as the hard disk) that they must be using and returns it to the respective browser. The same holds true for any other resource (image, MP3 file, zipped file, etc.) that you access on the internet.
Common methods of Internet access in homes include dial-up, landline broadband (over coaxial cable, fiber optic or copper wires), Wi-Fi, satellite and 3G/4G technology cell phones. Public places to use the Internet include libraries and Internet cafes, where computers with Internet connections are available. There are also Internet access points in many public places such as airport halls and coffee shops, in some cases just for brief use while standing. Various terms are used, such as “public Internet kiosk”, “public access terminal”, and “Web payphone”. Many hotels now also have public terminals, though these are usually fee-based. These terminals are widely accessed for various usage like ticket booking, bank deposit, online payment etc. Wi-Fi provides wireless access to computer networks, and therefore can do so to the Internet itself. (wiki)
Buffering in internet
Buffering is a situation which occurs when a streaming media player is saving portions of a streaming media file to local storage for playback. Most streaming media players buffer a small percentage of a streaming media presentation before beginning to play it. Buffering also may occur in the middle of a presentation when available bandwidth does not match the presentation’s required bandwidth.
How do search engines work?
A search engine does not search the entire Internet, but databases of Web pages. When a designer contacts a search engine for the addition of his website in the database, a program called Spider visits the site, reads the pages, indexes the contents and follows links to move on. Search engines like Google use algorithms to find pages with matter relevant to the keywords entered by the user. If the title or headings of the page contain the keywords, then it gets higher preference. Google also uses a patented algorithm called PageRank system that ranks a website based on how many sites have links to it and their ranks as well.