C: Cross - You solve a cross on bottom, like the layer by layer method. This could be done in less than 6 moves most of the time.

F: F2L - This stands for First Two Layers, and as the name suggests, you solve the first two layers in F2L pairs. There are 2 parts to the F2L, the intuitive and the algorithm. Normally the algorithm is naturally easier until you are very proficient at it before moving on to intuitive.

O: OLL- This stands for Orientation of the Last Layer. Your aim is to make all yellow sides face up. There are 57 algorithms. However, you only need to learn 7 algorithms to do this in 2 steps.

P: PLL- This stands for Permutation of the Last Layer. You permute(move) the pieces on the last layer to solve the entire cube. There are 21 algorithms.