Computers can do a lot. But it's the Internet that makes them come alive, allowing users to communicate and share data all across the world, over millions of miles, in fractions of a second. The Internet forms the connection underlying all computing, governing how software and hardware—regardless of vendor—work together. Here Doug Winnie explains the history of the Internet and the technology underlying the web, including IP addressing, routing, web servers, URLs, and the languages that allow computers to "speak" to each other over the Internet, such as hypertext and HTML. And any conversation about the Internet isn't complete without a mention of security. Doug explains how encryption works and why it's important to keeping your data safe online.