Phosphorylase and phosphatase are two types of enzymes that catalyze biochemical reactions involving substrates with phosphate groups. There are a few significant differences between the two. 

Phosphorylase catalyzes reactions that involve the transfer of phosphate groups between compounds. It plays a key role in adding a phosphate group to a phosphate acceptor. 

The main substrate involved is inorganic phosphate compound. 

Phosphorylase enzymes are classified into two major groups - Glycosyltransferases and Nucleotidyltransferases. 

Phosphatase catalyzes reactions that involve removing a phosphate group from a compound. It uses water to cleave phosphoric acid, resulting in the formation of phosphate ions and an alcohol byproduct. 

Phosphoric acid is the main substrate.

Phosphoric acid can be classified into a number of different enzyme types including about 104 families.