What is the Internet? What is TCP/IP? Bandwidth? Speed?

What is the Internet? or, “You Say Tomato, I Say TCP/IP”

What is the Internet, exactly? To some of us, the Internet is where we stay in touch with friends, get the news, shop, and play games. To some others, the Internet can mean their local broadband providers, or the underground wires and fiber-optic cables that carry data back and forth across cities and oceans. Who is right?

A helpful place to start is near the Very Beginning: 1974. That was the year that a few smart computer researchers invented something called the Internet Protocol Suite, or TCP/IP for short. TCP/IP created a set of rules that allowed computers to “talk” to each other and send information back and forth.

TCP/IP is somewhat like human communication: when we speak to each other, the rules of grammar provide structure to language and ensures that we can understand each other and exchange ideas. Similarly, TCP/IP provides the rules of communication that ensure interconnected devices understand each other so that they can send information back and forth. As that group of interconnected devices grew from one room to many rooms — and then to many buildings, and then to many cities and countries — the Internet was born.

The early creators of the Internet discovered that data and information could be sent more efficiently when broken into smaller chunks, sent separately, and reassembled. Those chunks are called packets. So when you send an email across the Internet, your full email message is broken down into packets, sent to your recipient, and reassembled. The same thing happens when you watch a video on a website like YouTube: the video files are segmented into data packets that can be sent from multiple YouTube servers around the world and reassembled to form the video that you watch through your browser.

What about speed? If traffic on the Internet were akin to a stream of water, the Internet’s bandwidth is equivalent to the amount of water that flows through the stream per second. So when you hear engineers talking about bandwidth, what they’re really referring to is the amount of data that can be sent over your Internet connection per second. This is an indication of how fast your connection is. Faster connections are now possible with better physical infrastructure (such as fiber optic cables that can send information close to the speed of light), as well as better ways to encode the information onto the physical medium itself, even on older medium like copper wires.

The Internet is a fascinating and highly technical system, and yet for most of us today, it’s a user-friendly world where we don’t even think about the wires and equations involved. The Internet is also the backbone that allows the World Wide Web that we know and love to exist: with an Internet connection, we can access an open, ever-growing universe of interlinked web pages and applications. In fact, there are probably as many pages on the web today as there are neurons in your brain, as there are stars in the Milky Way!

In the next two chapters, we’ll take a look at how the web is used today through cloud computing and web apps.