Do you know what has done if you execute “git pull”?
git fetch download new branches and data from a remote repository
git pull fetch from a remote repo and try to merge into the current branch
git pull equals
git fetch && git merge FETCH_HEAD
git pull --rebase equals
git fetch && git rebase
HEAD names the commit on which you based the changes in the working tree.
FETCH_HEAD records the branch which you fetched from a remote repository with your last git fetch invocation.
ORIG_HEAD is created by commands that move your
HEAD in a drastic way, to record the position of the
HEAD before their operation, so that you can easily change the tip of the branch back to the state before you ran them.
MERGE_HEAD records the commit(s) which you are merging into your branch when you run git merge.