[marcthe12]

I think the distinction is a soft fork or a hard fork. A soft fork is just a patchset over upstream and some people do not call it a fork. Hard fork mean that you are diverging from upstream, you do not longer follow upstream and you are fully separate from the upstream

[GoblinSlayer]

I think fork implies following upstream. If you don't follow, then it's a divorce, not a fork.

[account42]

No, "fork" means development has separated paths from original project. Changing some relatively minor parts but otherwise keeping close to upstream would be better called a "spin", especially when most of the changes are just to the default configuration.

It's a shame that GitHub messed up this term by calling any clone of a repository a "fork".

[pseudalopex]

Your definition of fork excludes many notable forks. I never heard someone call a software project a divorce.