In case your field of work or study refers to them differently, rockstars are people who think that their shit doesn’t stink, that they’re the best, and that its beneath them to work well and/or play well with others. They sometimes do quality work, and are doted upon by their peers for it, but in reality are hard to manage, hard to handle, and hard to mold into your team dynamics.
I think most businesses refer to these people as “prima donnas”. A “rockstar” is a person who’s shit actually DOESN’T stink, IS the best, AND is a modest, team contributor on top of it all.
In my experience, at least.