The documents listed in this chapter are about basic concepts related to either Git or GitHub.
If you have a problem (question) about some of the basic concepts please look for the GitUser's Manual, i.e. don't ask me. It's where I found most answers by the way.
If you have Git installed you should find the html document in the Git directory as ./doc/git/html/user-manual.html. It has a lot of valuable information about how Git works.