What would you use ENUM for in SQL?
Generally enums are for static lists, i.e. lists that never change. Departments is a bad choice because these can change at any time. Continents is good because these are highly unlikely to change, but countries would be bad because these do change. Think of things that are constants, such as seasons, months, day of week etc... You want to keep enums small. As a general rule that I apply personally, if a enum needs 10 or more entries, I create a regular list.