git merge:
+ does exactly what its name suggests
+ works most of the time
git rebase:
- not a common verb
- uses re- prefix although there's no "git base"
- literally does historical revisionism
- gaslights anyone who knows the truth
- probably kicks puppies when you aren't looking
- constantly wrecking shit
- basically only exists for "aesthetics"
- forces you into learning about "reflog"
My advice is to think of it as a misspelling of "git freebase".
They're both things that you probably shouldn't be doing on a regular basis.