There are summaries online, but seriously, this is a complex topic and you'll want to read about it in depth. Anyway, recommendations. Blake Snyder's Save the Cat is the single most useful book on writing I've ever read, and you should read it even if you don't read anything else here. The caveat is that it's intended for Hollywood screenwriting and has a fairly strict plot formula, which can make your writing formulaic and robotic if you misapply it. So when I recommend it, I like to recommend you read conflicting or supplementary opinions as well. Larry Brooks's Story Structure is a pretty good introduction to a basic four-act structure (my favorite variant on the three-act structure) and raises a few useful points that StC doesn't. (While I'm at it, I also like to recommend Self-Editing for Fiction Writers as a good primer for prose mechanics, but that's not really related to our discussion here.)
I'd say the most common structures include three acts, four acts (novels), five acts (Shakespeare plays), six acts (TV dramas), eight sequences (movies), and the fifteen beats (arranged into three acts, although imo it's four) of Blake Snyder's beat sheet. But they're all pretty much the same thing; they just divide the key events up in different ways.