[nchmy]

"multiple versions" = feature branches, possibly all in progress, probably all related. In a couple seconds, you can create a merge on top of all of them to join up their combined functionality/changes, work on top of that ON ALL OF THEM AT ONCE, and then squash all the relevant changes into the respective PRs that others (who are just using git) can review and merge into main.

At this point A LOT has been written in this and other threads, as well as lots of essays and tutorials about how jj just completely transforms your workflow. If you're curious, you'll seek it out. If not, that's fine as well.

[typpilol]

What does the history look like then? Just a single merge from a ton of branches or?

[KingMob]

The parent is describing the megamerge pattern, which is a way to work on multiple branches at once.

You don't have to do that, and you rarely push it to others. History looks the same as git, usually, although I end up rebasing more than I ever did in git, since it's easier and safer.