It's worth noting that knowing the difference between various configuration levels of git can be very beneficial sometimes.

For example, lets say you usually work with one set of user credentials.

git config --global user.name 'Jean-Luc Picard'
git config --global user.email 'captain@1701.de'

However, you have a project where you really don't want to use those credentials so you set up a local (per repository) config like this.

git config --local user.name 'John Luck Pickerd'
git config --local user.email 'not-the-captain@1701.de'

For that one project the local settings will take precedence over all other configuration levels (except worktree but that's another story) so whenever you interract with the repo (commit, push etc.) your local credentials will be used instead of the global ones.

Here a quick look at what is affected by which configuration level:

--system - affects all users on the current machine, logged in or otherwise
--global - affects only the currently logged in user and takes precedence over --system
--local - affects only the current repository and takes precedence over --system and --local
--worktree - affects only the currently active worktree (mostly useful when working with git worktree) and takes precedence over --system, --global and --local

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