Git facilitates collaboration on the same project by letting users work on separate branches. There are some guidelines to follow regarding branches.
There is one branch called master that must contain only working, validated features. At any time, the master branch should be operable and deliverable. It does not have to be complete (that takes time) but it must be operable. The version number of the master branch is the most recent version of the project.
A branch for each feature
To ensure that master is always in an operable state, development work is done on different branches. These branches can have names like develop-lennert if each user works on his/her own issues on his/her own branch, or names like develop-add-wiki if each issue is worked on in a separate branch. When a develop branch is complete (i.e. it solves the issues or adds the features it was created for) it can be merged into the master branch to apply the new changes.