Perfection is a flawless state where everything is exactly right. It can also be the action of making something perfect.
Since perfect things are without fault or flaw, perfection is a perfect condition — everything is 100% great. Of course, perfection is hard to find. People often use this word as a compliment for something that just couldn’t be better, as in "That red dress matches your red hair to perfection!” Also, if a musician is getting a song down pat, you could say she’s working on the perfection of the song: she’s learning to play it flawlessly.