Rules to play Rubiks Cube
Twists and Flips
A corner at a certain place can have three states. Algorithms that take a corner from one state to another twists a corner. For pratical reasons, twisting is considered undefined when a corner does not stay at the same place. Mathematically, twisting can still be defined, but only in a less intuitive way of little concern to us.
When viewed from the exterior toward the corner, a clockwise twist of 120