Parities are common in our solves(Almost 75% of our solves). There is 50% chance of OLL or PLL parity only and 25% chance of both the parities together.

PLL parity is only for even numbered cubes and not for odd nubered cubes. OLL parity is for all cubes. But 2x2 and 3x3 don't have any kind of parity. If you still got a parity in 3x3, reassemble the cube. Single Corner twist is not a parity. Just twist the corner and continue solving. r, r', l, l' refers to the slice layer of parity. * refers to turn 2 layers at once for 4x4 and 3 layers at once for 6x6.

Learn PLL: Beginner PLL(3 steps), Advanced PLL(2 steps), Master PLL(1 step).

Learn OLL: Beginner OLL(3 steps), Advanced OLL(2 steps),