Every repo, after an initial commit, starts by default with one branch and that is named master. It’s the branch that everyones’ branches get merged into and is largely the one from which developers pull changes. This makes it the most important – it’s the one that contains the latest changes, it’s the one that’s used by the build servers to power continuous integration. Therefore it needs special protection to ensure nothing bad happens to it.
Tools and process
Firstly, there should be safety measures in whatever git server hosting you use (GitHub, GitLab, BitBucket) to protect a master branch from being overwritten by a stray push command. But more importantly there should be a set process that every developer follows. One that doesn’t get in the way of productivity but rather helps collaborative development thrive. These template workflow entries give you a blueprint to get started. And look, already you know never to push to master.