Editing individual files directly from gitlab GUI

I am a beginner in git and gitlab.

In my shop, we use git using a self-hosted gitlab implementation.

I have 2 basic questions on git/gitlab

Question1. From gitlab’s GUI, it is possible to edit an individual file by clicking on the edit button and making the necessary changes as shown below.

In the above scenario, git commands like git add <filename> and git commit -m <comment> are internally run. Right ?

Question2. Is it true that any changes done to a file in a remote repo is originally done locally in someone’s PC (local repo) and pushed back to the remote repo ?
If this is true, then how will the scenario mentioned in Question1 achieved (editing file directly from GUI) ?
Gitlab uses some temp filesystem to store the file and run “git add ” and “git commit -m ” commands or gitlab keeps the file in memory and runs run “git add ” and “git commit -m ” commands?