Git is a source control system (like SVN, CVS and others) which is both very strong and enables work without connection to a server. You can read about it in Wikipedia.
When connected using CA VPN or Eduroam on the campus:
git clone ssh://<cshost>.cs.huji.ac.il/path-to-repo
If you set up a git repository on the university servers and want to access it from outside without VPN or Eduroam on the campus, you should first set up ssh tunneling as described in Revision control. After that you can clone the repository to you machine (on some OS the tunnel command won't let you enter farther commands, so you may need to open a new terminal on your local machine, while the tunnel terminal stays open):
For example:
# Creating the tunnel on bava.cs.huji.ac.il jump server:
ssh -L 22222:<cshost>:22 -fN <csuser>@bava.cs.huji.ac.il
# Cloning the git repository using that tunnel:
git clone ssh://<csuser>@localhost:22222/path-to-repo
You will need an OTP for the tunnel setup, and your cs password for the clone operation.
After you do it, the remote repository is saved and you don't need this long address again. You can further reduce the need for your CS password when communicating with the repository by setting a ssh key