The five predicables — genus, species, differentia, property and common accident — explain how a universal relates to the essences or attributes of its instances.
The ten categories — substance and nine accidental categories — sort things and attributes by their most basic kind of being within the classical scheme.
For example, whiteness falls under quality among the categories; “white,” said of a human, is non-essential and belongs to common accident among the five predicables, since whiteness can occur in other species too.
The same item may be analyzed in both ways, provided we keep the questions of the two classifications distinct.