PLL or Permutation of the Last Layer is the fourth and last step of the CFOP method, which aims to permute the pieces of the last layer to have the 3x3 fully solved. This step is fully algorithmic, and consists of 21 cases.
Two look PLL is a smaller subset which orients the top layer in two stages. First, the corners are oriented - two cases, Then the edges are oriented - 4 cases.
Did you know that you can recognize the PLL case looking at only two sides?
By learning new, easy to recognize patterns, you can improve your recognition time significantly. Click on the link below to learn more!
Some PLLs are just conjugates of other OLLs. While these versions might seem longer, they are easier to learn and execute because they rely on your practice and muscle: