How the Internet Works: A Primer

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The Internet is a huge network of computers that send messages and other data to each other. For the most part, it works using the same underlying infrastructure used for telephone voice calling.

The Internet Connects Smaller Networks
In a very simple computer network, two computers are linked together in order to communicate. Typically, this is accomplished either physically, with a cable that uses the Ethernet networking protocol, or wirelessly, via the Wi-Fi protocol. You could expand that network to include more computers easily but you'd need more connectors. To connect 10 computers, for example, 45 cables would be required, with nine plugs for each computer. To avoid this problem, a miniature computer, known as a network router, is used to direct data traffic efficiently among computers. When one router is connected to another, the network is able to scale without limit, notes Mozilla.

Communicating over the Internet
On the infinite network that is the Internet, data from individual computers and networks is sent to the user's Internet service provider (ISP). Each ISP runs special routers capable of communicating with other ISPs' routers. Users can communicate with a specific computer on the Internet either by typing in the computer's Internet protocol (IP) address, which consists of four numbers separated by dots, or by using its domain name, such as, according to Mozilla.

Traditional Internet Infrastructure
Traditionally, the routed data traffic has run largely over cable networks already connected to businesses and homes. Devices called modems convert the data from business and home networks to information that can be managed over the long-standing telephone infrastructure, says Mozilla. Instead of the point-to-point circuit switching used in traditional voice calling, however, the Internet uses technology known as packet switching for routing data among myriad computers.

Is the Internet the Same as the Web?
While the two words are sometimes used almost interchangeably, the Internet is not the same thing as the Web. Like email and Inter relay chat, the Web is a service built on top of the Internet. For typing in domain names and browsing websites, end users rely on Web browser software. Web browsers send messages to certain computers on the network, which are known as Web servers, Mozilla observes.

Rise of the Mobile Internet
With the surge in popularity of mobile smartphones and tablet computers, a mobile Internet has arisen that uses the same basic underpinnings as older cellular networks, while adding newer communications standards. Each "cell," or geographic area, in a cellular network has a tower at the center. The tower passes information to and from satellites. Smartphones and other cellphones connect to the Internet much like PCs but wirelessly. The phones come with built-in antenna for sending information to the towers and fetching data. For the sake of efficiency, the voice and data channels of cell phones are separated, with IP and short message service signals going out over the data channel. RF (radio frequency) energy is used for transmitting data between the phone and the Internet. A modem is used to get information to and off of the mobile carrier's network. The mobile carrier sends packets of data to destination addresses on the Internet. In addition to using mobile carriers' networks, smartphones and tablets can also communicate over the Internet through Wi-Fi hot spots, according to EngineersGarage.