How does the Internet work?

The Internet is centered around regional "backbones" usually owned by a major communications company. These companies connect their backbones at strategically located network access points, usually found in major cities, that allow users of one network to communicate with those on other networks. Routers direct information between these different networks.
From the perspective of the end user of the Internet, Internet Service Providers are required to access this network using personal devices, usually by purchasing a subscription account billed monthly. Each personal device that a user connects to the Internet is given a unique IP address, which is a series of four numbers, to identify it.
Internet connections can be used in a number of different ways, but the primary use is to connect to the World Wide Web. The Domain Name System is used to map text names for website addresses to IP addresses, so that users don't have to remember a series of arbitrary numbers to connect to each website. The text that represents the IP address of a website is called the Uniform Resource Locator, or URL, and follows a specific format.