title: Use same branch more than once
body: <p>I am new to git, and I am assuming that if I can use only one branch for all project. After I commit my code into a branch -- <code>subBranch</code>, and merge it into the <code>master</code>. Then I did some other change. May I commit them into the <code>subBranch</code> again and merge into the <code>master</code>, or I have to make a new branch?</p>