Cranksets power your whole drivetrain and make you go faster and fastest. Upgrading the crankset on any bike will radically transform the feeling you get when you push hard on the pedals.
Cranksets are not standard across brands and often change considerably within a brand. There is Square Taper, Octalink, Octalink II, Hollowtech, Hollowtech II, BB30, ISIS, Ultra Torque, and a few others.
Always make sure that your crankset fits the bottom bracket you already have.