Once you’re happy with your changes, you’ll want to merge them back into the main branch so that they make their way into the final product.

A - B - C main
D - E other_branch

If you merge other_branch into main, Git combines both branches by creating a new commit that has both histories as parents. In the diagram below, F is a merge commit that has C and E as parents. F brings all the changes from D and E back into the main branch.

A - B - C - F main \ / D - E other_branch

1git log --oneline --graph --all

How does merging happen?

Let’s say we start with this:

A - B - C main
D - E vimchadsonly

And we merge vimchadsonly into main by running this while on main:

1git merge vimchadsonly

The merge will:

• Find the “merge base” commit, or “best common ancestor” of the two branches. In this case, “A”.
• Replays the changes from vimchadsonly onto main starting from the best common ancestor (so, starting from “A”, apply all changes of main into a new commit “F”, and then all changes from vimchadsonly on “F” as if were “A”)
• Records the result as a new commit, in our case “F”.
• “F” is special because it has two parents, “C” and “E”.

After:

A - B - C - F main \ / D - E vimchadsonly

References

• boot.dev

Next -> git-fast-forward-merge