I used git checkout -b to create a new branch. I think that git branch does the same thing.
How do these two commands differ, if they differ at all
git checkout -b BRANCH_NAME creates a new branch and checks out the new branch while git branch BRANCH_NAME creates a new branch but leaves you on the same branch.
In other words git checkout -b BRANCH_NAME does the following for you.
git branch BRANCH_NAME # create a new branch
git switch BRANCH_NAME # then switch to the new branch