Pattern competition doesn't include a whole lot of "3-D" stuff like hovering, harriers etc. Think big loops that aren't pinched and exit at the exact same altitude that they started at with a roll at the top. Square loops with a half roll on each side and stuff like that. Snap rolls, slow rolls that don't change altitude or veer off course and are perfectly centered and stuff like that. Cuban eights, reverse cuban eights, diamond loops, round loops with a snap roll on top, and much more.
It's sort of like figure skating with RC airplanes and judges rating your flying. You might think of it as the RC version of CL stunt.

Pattern planes are smooth flying go exactly where you point them planes that are designed to make flying the pattern as easy as possible. They are also excellent sport planes by the way and that's what most people use them for.