When it's time to release that code to users of the website, the programmers then need to copy a specific version of the code to one or more web servers, which serve the code to users' web browsers. This is referred to as "deploying" the code. Sometimes the deployment step can be pretty complicated.
Sometimes programmers want to quickly share a demo, example, or prototype with other people, but without having to set up or perform a whole deployment process. That's where RawGit came in.
That's a lot of requests using up a lot of bandwidth, but RawGit's secret is that it was very simple behind the scenes. It did very little work to handle a request, and it then cached the result of that work so that in the future it wouldn't have to do any work to handle more requests for the same file. So it looks very impressive, but behind the scenes it really wasn't too complicated.
Hopefully that wasn't too boring or technical. 😄