Costumes are used in concert with other aspects to portray a characters profession, gender role, personality and / or social class. Costumes can be used to disclose information about the historical era, time of day, geographic location or even the season of a theatrical performance. Even weather conditions can be hinted at through the use of costumes, such as characters dressed in rain coats or carrying umbrellas.

In some cases theatrical costumes are a type of mimicry that depicts how a costume designer sees the character. A type of caricature can be put together with the aid of unique theatrical costumes to express what a given character may wear if he or she were to exist in the real world yet with his or her fictional flairs. Sometimes costumes are used to exaggerate a particular aspect of a character.

If it were not for costumes, audiences of theatrical performances would have a difficult time figuring out which character is related to whom and which role belongs to which character. Though most audiences take costuming for granted, it is really equally important as the script and set of the performance.

Costumes can have similar significance in non-theatrical areas of life as well. We are all familiar with the kimono and its association with Japan and Japanese culture, just as the kilt makes one think of Scotland or Scotsmen. These national costumes express regional identity and unique nationality.

There are various holidays at which time it is traditional to wear costumes. Halloween is a prime example of one of the greatest and most well known costume holidays. Costumes are a very important part of the Halloween tradition. Mardi Gras is also a costume focused holiday where nearly everyone involved wears beads and other Mardi Gras themed apparel.

Halloween costumes typically involve scary or supernatural costumes such as vampires and witches, whereas Mardi Gras costumes traditionally involve fantasy characters such as jesters. Christmas and Easter are holidays where certain people take on mythical roles and costumes that correlate, in this case Santa Claus and the Easter Bunny.