The Internet is a world-wide network of computers and computer-related things which enables almost instantaneous information transfer and communication between people who live far apart. Most PPC activity takes place on the Internet (other than Gatherings). If you are reading this wiki, then you probably already know about the Internet, hence the shortness of this article.
However, that isn't true of everybody. Bafflingly, although nearly all fan material is Internet-based, many badfics portray the Internet incorrectly. There are many "super hacker" Sues and Stus that display zero knowledge of how the Internet works, or even how computers in general work. This might be because using the Internet and actually understanding how it works are two different things. Additionally, many mainstream depictions of computer skills are highly misleading: typing really fast does not imply somebody is good at hacking computers, nor can someone use "the Internet" to remotely affect things like alien spaceships.
The Internet is available on some or all consoles, and many other devices in HQ, such as personal computers and gaming systems, also seem to be Internet-enabled. This is likely subject to the whims of the Ironic Overpower as much as anything else in HQ. HQ's Internet seems at least partially related to Inter-Console Electronic Post, which is HQ's main internal communication system.