It has evolved into way more than that, societies, krewes, orders, all established in partial secret to further the masked balls and parades steeped in ancient folklore and ideals. In Mobile and Montgomery, the celebration is through Balls, some formal, some not. The Balls all have their rituals to remember things that are now lost to many except on the inside. In New Orleans, there is a whole other drama going on with parades and other histories. Basically, it's ancient Egyptian ideals, mixed with Greek orders, Catholic nomenclature, Native American history, and slave mysticism all tied up with Southern and French accents.
...and damn good music!