INTERNET

The concept of data communication  - transmitting data between two different places, connected via some kind of electromagnetic medium, such as radio or an electrical wire - actually predates the introduction of the first computers. Such communication systems were typically limited to point to point communication between two end devices. Telegraph systems and telex machines  can be considered early precursors of this kind of communication. The earlier computers used the technology available at the time to allow communication between the central processing unit and remote terminals. As the technology evolved new systems were devised to allow communication over longer distances (for terminals) or with higher speed (for interconnection of local devices) that were necessary for the mainframe computer  model. Using these technologies it was possible to exchange data (such as files) between remote computers. However, the point to point communication model was limited, as it did not allow for direct communication between any two arbitrary systems; a physical link was necessary. The technology was also deemed as inherently unsafe for strategic and military use, because there were no alternative paths for the communication in case of an enemy attack.
As a response, several research programs started to explore and articulate principles of communications between physically separate systems, leading to the development of the packet switching model of digital networking. These research efforts included those of the laboratories of Vinton G. Cerf at Stanford University, Donald Davies (NPL), Paul Baran (RAND Corporation), and Leonard Kleinrock at MIT and at UCLA. The research led to the development of several packet-switched networking solutions in the late 1960s and 1970s, including ARPANET, Telenet, and the X.25 protocols. Additionally, public access and hobbyist networking systems grew in popularity, including unix-to-unix copy (UUCP) and FidoNet. They were however still disjointed separate networks, served only by limited gateways between networks. This led to the application of packet switching to develop a protocol for internetworking, where multiple different networks could be joined together into a super-framework of networks. By defining a simple common network system, the Internet Protocol Suite, the concept of the network could be separated from its physical implementation. This spread of internetworking began to form into the idea of a global network that would be called the Internet, based on standardized protocols officially implemented in 1982. Adoption and interconnection occurred quickly across the advanced telecommunication networks of the western world, and then began to penetrate into the rest of the world as it became the de-facto international standard for the global network. However, the disparity of growth between advanced nations and the third-world countries led to a digital divide that is still a concern today.
Following commercialization and introduction of privately run Internet service providers in the 1980s, and the Internet's expansion for popular use in the 1990s, the Internet has had a drastic impact on culture and commerce. This includes the rise of near instant communication by electronic mail (e-mail), text based discussion forums, and the World Wide Web. Investor speculation in new markets provided by these innovations would also lead to the inflation and subsequent collapse of the Dot-com bubble. But despite this, the Internet continues to grow, driven by commerce, greater amounts of online information and knowledge and social networking known as Web 2.0.

General Search Engines
Alexa Web Search: analyzes site traffic including ranking, global users, pages linking to the site, and links to related pages of interest
AllTheWeb : returns results quickly from a database gathered by the Yahoo! crawler; offers multimedia and news searches; has a good advanced search interface
AltaVista : searches Web sites with advanced Boolean and field search options. See also Babel Fish, the AltaVista translation service.
Ask.com : general search engine enhanced by a number of specialty searches including a dictionary, thesaurus, currency converter, encyclopedia, maps, news and more
Bing : Microsoft engine that displays excerpts from sites retrieved by your search and offers related search suggestions; multimedia and other deep Web results are also displayed. Bing focuses on searches related to making a purchase decision, planning a trip, researching a health condition, and finding a local business. Also check out Bing Maps Beta.
ChaCha : search engine that offers live human guides to help answer queries; focuses on questions from mobile devices
Exalead : offers concept clustering of results, thumbnail images of retrieved sites, and customization options such as organization of results by file type, geography or modification date
Factbites : searches for full topic matches and returns meaningful, full sentence excerpts of sites in its results list
Google : Web's most popular search engine that retrieves results in real time as you type your search. Also check out Eco Smart Search.com, a Google-powered search engine with a black background display that saves energy.
Hakia : organizes results into types of information sources, including "credible " sites recommended by librarians
iSEEK Education : offers authoritative resources from university, government, and established noncommercial providers; organizes results into concept clusters, and also allows users to recommend and rate sites
Lycos : general search engine that also offers searches of a few deep Web content sources including people look-up, yellow pages, and multimedia
Quintura : displays a type of tag cloud with keywords related to your search that can be selected to generate new results
Search Edu.com : service that limits results to the .edu, domain; also offers to search well-known dictionaries, encyclopedias, almanacs, etc.
Snappy Fingers : searches millions of Frequently Asked Questions (FAQs) for answers to user queries
Sproose : searches Yahoo! and allows users to comment on and vote on its search results
Webbrain : offers results in visual layout of related terms for subsequent searching
Wolfram Alpha : enter a question or calculation, and Wolfram Alpha uses its built-in algorithms and own collection of data to compute the answer
Yahoo : portal with a general Web search and many other content services.