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
Essentially :
A-git branch lets you create a branch plain and simple.
B -git checkout -b allows you to create a branch and switch to it at the same time.
When will you use which ? 1- git branch when you want to create a branch but stay on the current branch. 2- git checkout -b when you want to create and switch. If you look at it is intuitive to create a branch and switch to it. So the choice is yours :)