I am talking about this:
"SourceForge.net maintains a geographically-distributed network of mirror servers, which receive copies of the files and dispense them to users."
So, does github has the same automatically mirrored backup of our projects and files? I am having big trouble trying to find that information.
Yes in a way. Git is a distributed source control system. But only if others are using the repository. Some projects will have hundreds of offsite replications. Others sadly very few.
But these off site copies are not available to you directly
Yes, it is called DGit for Distributed Git: