What is Repo and Why does Google use it?

Question

When I wanted to get Android source code, I knew that I have to use "repo". So what is repo? Why do they use repo and not just use GIT?, and is there a GUI for repo that enables me to pause/resume syncing, because every time I get disconnected occasionally it seems that repo starts syncing from the beginning!

Answer 1

Repo and git - what they are, what they are for - is explained on source.android.com

To work with the Android code, you will need to use both Git and Repo.

Git is an open-source version-control system designed to handle very large projects that are distributed over multiple repositories. In the context of Android, we use Git for local operations such as local branching, commits, diffs, and edits.

Repo is a tool that we built on top of Git. Repo helps us manage the many Git repositories, does the uploads to our revision control system, and automates parts of the Android development workflow. Repo is not meant to replace Git, only to make it easier to work with Git in the context of Android. The repo command is an executable Python script that you can put anywhere in your path.

There's no UI for Repo, as far as I can tell, but there's quite a bit of guidance on the site above for controlling what Repo is doing from the command line.