Git: Merge commits, Squash and merge, Rebase

 Let's start by the following example:

Now we have 3 options to merge changes of feature branch into master branch:

1. Merge commits
   Will keep all commits history of the feature branch and move them into the master branch
   Will add extra dummy commit.

2. Rebase and merge
   Will append all commits history of the feature branch in the front of the master branch
   Will NOT add extra dummy commit.

3. Squash and merge
   Will group all feature branch commits into one commit then append it in the front of the master branch
   Will add extra dummy commit.

You can find below how the master branch will look after each one of them.

In all cases:
We can safely DELETE the feature branch.

Source: https://stackoverflow.com/questions/2427238/what-is-the-difference-between-merge-squash-and-rebase