When I've looked up libraries in GitHub in the past (after finding others talk about libraries from blogs and such), I could either download the compiled code or download the source code. Say, if it was in C#, some sources had only the .dll libraries that I could download and reference in my code but never see the source code. But some sources had the source code in C# or VB that I could also download and put into my project(s), but I'd unlike the .dll's I could see the source code myself.
It's been maybe 8 or so years since I've used GitHub (the team I'm in now buys 3rd party libraries so I get our "shared" code from those vendors directly). But that's my experience.
“some sources had only the .dll libraries that I could download and reference in my code but never see the source code.”
Gotcha.
I knew of a company that bought the “source code” for something or other. They got the source code but all of the comments were stripped out.