"Dress up" can either refer to wearing the best clothes an individual has, or it can mean wearing an outfit that resembles a particular role. An event that requires attendees to dress up in fancy clothing can require anything from suits and sundresses to tuxedos and evening gowns, depending on the time and formality of the event.
Costume parties are also popular dress up occasions, as attendees wear clothing, makeup and masks intended to transform their appearance. Common costumes include people from another era, supernatural entities, pop culture icons and real and imaginary creatures.
Certain cultural events, holidays and religious happenings are affairs where both types of dress up are common.