You have finished working on your branch, everything works, and you want to use git to merge the branch into the master.
To merge means to bring back in the master all the changes made in the branch.
First move into the master using
git checkout master
This is because now you can say “ok, bring all the changes made in the branch branch_name here”!
You can do this with the command
git merge branch_name --no-ff
Using –no-ff you will keep all the commit messages before the merge!
Now… Push your work!