Originally a stereotype was an impression taken from a form of movable lead type and used for printing instead of the original type. This was generalized into a metaphor for repeating a set of ideas identically with no changes (as would have been possible in a form of movable type).
In modern usage, the metaphorical meaning predominates. The term is generally used to describe an oversimplified mental picture of some group of people who are sharing a certain characteristic (or stereotypical) qualities. The term is thus often used in a negative sense, with stereotypes being seen by many as illogical yet deeply held-beliefs that can only be changed through education.
In computing, the negative connotation does not apply; stereotype is also a concept in the Unified Modeling Language, where it is used to encapsulate behaviors. Thus, a stereotype is used as a vehicle for communicating software requirements and designs.
Common stereotypes of the past included a variety of allegations about various racial groups (see: racial stereotype and racial profiling) and predictions of behavior based on social status and wealth (See social stereotype).
In literature and art, stereotypes are clichéd or predictable characters or situations. For example, the stereotypical devil is a red, impish character with horns and a pitchfork.
Common stereotypical characters
See also: archetype, stock character, counterstereotype (antonym)