How does Sync work when working with Git in Visual Studio 2013?

How does Git Sync button work in Visual Studio Team Explorer? What are the actual executed Git commands and their order?

What is the use of sync command in git?

git-sync is used for syncing a personal fork with the upstream repository the personal fork was created from. Syncing here means updating all the branches in the personal fork that are also present in the upstream repository.

What is the difference between sync and push in git?

Commit All and Push: same as Commit All, but pushes changes to the remote repository. Commit All and Sync: saves changes to local repository, pulls changes from the remote to sync with local changes, and then pushes changes to the remote repository.

It does the equivalent of a fetch + merge + push, which is the same as pull + push