Using Atlassian’s Git tutorial (link updated) as a reference.
Git checkout:
The git checkout command lets you navigate between the branches
created by git branch. Checking out a branch updates the files in the
working directory to match the version stored in that branch, and it
tells Git to record all new commits on that branch. Think of it as a
way to select which line of development you’re working on.Source: https://www.atlassian.com/git/tutorials/using-branches#git-checkout
Git pull:
You can think of git pull as Git’s version of svn update. It’s an easy
way to synchronize your local repository with upstream changes. The
following diagram explains each step of the pulling process.Source: https://www.atlassian.com/git/tutorials/syncing#git-pull
Git fetch:
The git fetch command imports commits from a remote repository into
your local repo. The resulting commits are stored as remote branches
instead of the normal local branches that we’ve been working with.
This gives you a chance to review changes before integrating them into
your copy of the project.Source: https://www.atlassian.com/git/tutorials/syncing#git-fetch