In github,forking the repo is creating whole mother repo, making the fix and submitting pull request.
Earlier, my understanding was limited that you edit some codes, then submit pull request or even one step backward, download on your local machine, edit codes and submit pull request.
But you can do it forking, then decide whether to submit pull request or just put in your github repo though there will be 'forked from .... mother repo's public link' as written right under title (which is README)
I mean it's not only for the code editing process, but some document-er decides to add wiki about project, then s/he forks it and may choose to or not to submit pull request.
Below is screenshot of fork tree of BRAVE token repo:
PS: My github is github.com/sbibek086