git fetch pulls down the code from the remote server to your tracking branches in your local repository. If your remote is named origin (the default) then these branches will be within origin/, for example origin/master, origin/mybranch-123, etc. These are not your current branches, they are local copies of those branches from the server.
git pull does a git fetch but then also merges the code from the tracking branch into your current local version of that branch. If you're not ready for that changes yet, just git fetch first.
