What are ENUMs used for in MySQL?

Answer 1

Use of ENUM takes less storage space and is much faster than if you stored the actual strings since MySQL internally represents each choice as a number. I.e. female = 0, male = 1, etc.

Answer 2

ENUM is used to limit the values that persist in the table. The following example illustrates the best use of ENUM.
CREATE TABLE months (month ENUM ‘January’, ‘February’, ‘March’,);
INSERT months VALUES (’April’);