In a typical Git + GitHub workflow, you’ll have have your work in a folder (repository) on your local computer and also a linked copy on a remote repository (origin), in this case GitHub.
You can make changes in your local repository (most common) or your remote repository.
To synch the remote repository with local changes you Push.
To synch a local repository with remote changes you Pull.
After you make changes to a file you will need to commit them so that Git creates a snapshot of the file at it’s current state (saving the file does not commit the changes to git). To this you:
More info on GitKraken Client Interface basics