The Internet is a worldwide, publicly accessible series of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government networks, which together carry various information and services, such as electronic mail, online chat, file transfer, and the interlinked web pages and other resources of the World Wide Web. DIFFERENCE BETWEEN INTERNET & WWW
The Internet and the World Wide Web are not synonymous. The Internet is a collection of interconnected computer networks, linked by copper wires, fiber-optic cables, wireless connections, etc. In contrast, the Web is a collection of interconnected documents and other resources, linked by hyperlinks and URLs. The World Wide Web is one of the services accessible via the Internet, along with many others including e-mail, file sharing and others.. The Internet protocol suite is a collection of standards and protocols organized into layers so that each layer provides the foundation and the services required by the layer above. In this scheme, the Internet consists of the computers and networks that handle Internet Protocol (IP) data packets. Transmission Control Protocol (TCP) depends on IP and solves problems like data packets arriving out of order or not at all. Next comes Hypertext Transfer Protocol (HTTP), which is an application layer protocol. It runs on top of TCP/IP and provides user agents, such as web browsers, with access to the files, documents and other resources of the World Wide Web. Internet protocols
In this context, there are three layers of protocols:
* At the lower level (OSI layer 3) is IP (Internet Protocol), which defines the datagrams or packets that carry blocks of data from one node to another. The vast majority of today's Internet uses version four of the IP protocol (i.e. IPv4). *
* ICMP (Internet Control Message Protocol) also exists at this level. ICMP is connectionless; it is used for control, signaling, and error reporting purposes. * TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) exist at the next layer up (OSI layer 4); these are the protocols by which data is transmitted. TCP makes a virtual 'connection', which gives some level of guarantee of reliability. UDP is a best-effort, connectionless transport, in which data packets that are lost in transit will not be re-sent. -------------------------------------------------
Common uses of the Internet
The concept of sending electronic text messages between parties in a way analogous to mailing letters or memos predates the creation of the Internet. Internet e-mail may travel and be stored unencrypted on many other networks and machines out of both the sender's and the recipient's control.
The World Wide Web
Many people use the terms Internet and World Wide Web (or just the Web) interchangeably, but, as discussed above, the two terms are not synonymous. The World Wide Web is a huge set of interlinked documents, images and other resources, linked by hyperlinks and URLs.
These hyperlinks and URLs allow the web-servers and other machines that store originals, and cached copies, of these resources to deliver them as required using HTTP. HTTP is only one of the communication protocols used on the Internet.
Web services also use HTTP to allow software systems to communicate in order to share and exchange business logic and data.
Dial-up access is a form of Internet access via telephone line. The client uses a modem connected to a computer and a telephone line to dial into an Internet service provider's (ISP) node to establish a modem-to-modem link, which is then routed to the Internet. Dial-up requires no additional infrastructure on top of...