The merge command is used to bring together changes from two branches. For example, if you have a feature branch that is branched off of the master branch. When you are done with that feature branch you can use the merge command to merge it back to master.
git checkout receiving-branch git merge feature-branch git push origin receiving-branch
We will assume receiving-branch to be master for the example above.
The merge command will bring all the commits from the feature branch into the master branch.
If you want to revert the merge you have started. Use the following command:
git merge --abort