Section 6 - How does the Internet work?

When you request or send information such as a webpage or email, the computer breaks the request into smaller, more manageable pieces called packets. Each of these packets contains both the sender's Internet address and the receiver's address. Every packet is sent first to a gateway computer that understands a small portion of the Internet. This gateway computer reads the destination address and forwards the packet to an adjacent gateway, closer to the packets destination, it will in turn read the destination address and so forth across the Internet until a gateway recognizes the packet as belonging to a computer within its immediate neighborhood or domain. Regardless of what operating system you use (Mac, PC, or Unix) to connect to the Internet, the computers all basically speak the same language, which allows you to exchange information with someone next door or across the planet.

Because a message can be divided in numerous packets, each packet may be sent by a different route across the Internet. Because the IP just delivers the packets, they can arrive in a different order than the order they were sent in. The Transmission Control Protocol (TCP) has the job of putting them back in the right order.