Great! We now know how to commit and branch. Now we need to learn some kind of way of combining the work from two different branches together. This will allow us to branch off, develop a new feature, and then combine it back in.

The first method to combine work that we will examine is git merge. Merging in Git creates a special commit that has two unique parents. A commit with two parents essentially means "I want to include all the work from this parent over here and this one over here, and the set of all their parents."

It's easier with visuals, let's check it out.

Before merge

Git before commit

Here we have two branches; each has one commit that's unique. This means that neither branch includes the entire set of "work" in the repository that we have done. Let's fix that with merge.

We will merge the branch bugFix into master (and from master).

git merge bugFix

After merge

Git after commit

Woah! See that? First of all, master now points to a commit that has two parents. If you follow the arrows up the commit tree from master, you will hit every commit along the way to the root. This means that master contains all the work in the repository now.

Solve the challenge