The Definition of Internet.
The Internet is a global network connecting millions of computers.
More than 190 countries are linked into exchanges of data, news and opinions. According to Internet Live Stats, as of December 30, 2014 there was an estimated 3,037,608,300 Internet users worldwide. The number of Internet users represents nearly 40 percent of the world's population. The largest number of Internet users by country is China, followed by the United States and India. In September 2014, the total number of websites with a unique hostname online exceeded 1 billion.
This is an increase from one website (info.cern.ch) in 1991.Unlike online services, which are centrally controlled, by design, the Internet is decentralized. Each Internet computer, called a host, is independent. Operators can choose which Internet services to use and which local services to make available to the global Internet community. Remarkably, this anarchy by design works exceedingly well. There are a variety of ways to access the Internet. Most online
Relation between Domain Names and IP address
A domain name is very similar to an address forwarding service. The domain name is the address people type in their web browser to get to your web site. The domain name then points to the "real" address that contains your web site. The "real" address is called the IP address and is a series of numbers, such as 188.8.131.52. This IP address then points to the location on the server that contains your web site files.
The reason we use domain names instead of IP addresses is because for most people a name, rather than a series of numbers, is much easier to remember. So, your domain name points to your IP address, which in turn points to your web site which allows users all across the Internet to view your web pages.
Data packets and Packet switching
Refers to protocols in which messages are divided into packets before they are sent. Each packet is then transmitted individually and can even follow different routes to its destination. Once all the packets forming a message arrive at the destination, they are recompiled into the original message.
Most modern Wide Area Network (WAN) protocols, including TCP/IP, X.25, and
Frame Relay, are based on packet-switching technologies. In contrast, normal telephone service is based on a circuit-switching technology, in which a dedicated line is allocated for transmission between two parties. Circuit-switching is ideal when data must be transmitted quickly and must arrive in the same order in which it's sent. This is the case with most real-time data, such as live audio and video. Packet switching is more efficient and robust for data that can withstand some delays in transmission, such as e-mail messages and Web pages.
A new technology, ATM, attempts to combine the best of both worlds -- the guaranteed delivery of circuit-switched networks and the robustness and efficiency of packet-switching networks.
The Function of an Internet Router
All of these networks rely on NAPs, backbones and routers to talk to each other. What is incredible about this