Well, google it. Here's an article on the Wikipedia.
TL;DR: Some calculations take a really long time, so when you have multiple computers that work on the same thing simultaneously, where each one calculates its own part of the whole task, the work is going to be done faster. This is exactly what this code is supposed to do. But because it's a school project I don't intend to make it flexible (maybe API in the future)
Currently there is no full documentation in English, sorry.