Reset a file or full

To reset a file to the original file
To reset a file to its orginal file (remove your changes to the file abc.txt)
# With Git 2.23
git restore abc.txt
# With older version of git
git checkout -- abc.txt
To do full reset a file (reset the file back to original remote format)
git checkout @ -- abc.txt
git checkout HEAD -- abc.txt

To reset a local branch exactly to the remote

git fetch origin
git reset --hard origin/master