git merge <branchname1> <branchname2>
Merge a branch into a target branch
This command is used for combining the changes made in <branchname1> and <branchname2>.
It does this by creating a new commit which incorporates the changes of both branches. The changes from <branchname1> and <branchname2> are compared and if there are non-conflicting changes in the lines of the same files, the lines are merged together automatically.
In case of conflicts, it requires manual resolution.
Variations of this command include git merge --no-commit <branchname> which merges the branch but does not create a new commit, and git merge --squash <branchname> which allows you to combine commits from the merged branch into one commit on the current branch.