Gidday guys

Apologies in advance for this question, but what is capping?
I often read posts where guys talk about "capping" their hulls during restorations, or new builds being capped.
Looking at photos, I'm guessing the deck is glassed to the hull rather than having a rubbing strip/gunnel over
the joint.
I'm also amazed at seeing photos of beautiful gel coats on deck and hull molds then all buffed back to bare
glass where the two halves have been glassed together, do you just have to do a gel coat repair where the new seam is?

Thanks for the education