What are release branches?

Answer 1

This refers to a software development practice. The main collection of code is called the trunk. All the developers do their main work in the trunk. A branch is when someone pulls a copy of the software repository into a separate collection. That way, they can work on it without disturbing the trunk. So if they are doing major work and need to experiment, and they are likely to break things that are working, they will create a branch. Then when they are finished, they will merge all the beneficial changes that meet the project goals into the current trunk revision. Anyway, when the team decides to make a release version, a branch will be created so it can be frozen at a certain trunk revision while the developers continue working on the trunk for the next release. Then some changes may be made in the branch created for the current release, such as some minor cleanup, removal of a few changes that made things unstable, some optimizations, etc. Then the copy from the branch is released to the public.