system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: What is the purpose of the Raspberry Pi?
gpt
Sometimes you have a project that needs the ability to do the full logic of a computer, but you don't want to devote a whole computer to doing it. Historically, this usually meant something called a *microcontroller* - a tiny computer chip built into devices that runs on very little power. But microcontrollers aren't very powerful and aren't very hobbyist friendly, because they're tiny and (historically) a bit difficult to program.

So the Raspberry Pi is something between a microcontroller and a full PC: it's powerful enough to run small web servers or emulate old games, but much cheaper than a full modern computer, so it's a good option for building into larger projects. For example, people build arcade machines using them, with the Pi emulating a game and wired up to the controls on the outside of the case. A lot of its uses are just "it's a very cheap low-power computer you can use for anything that isn't performance-dependent".

The original purpose was actually just a very cheap lightweight computer for poor nations, but it became really popular because of hobbyists.