a portrait is a representation of an individual person. a photographic portrait is understood to be a good quality image that not only captures a person’s physical likeness, but also person’s character, generally in a manner that is attractive and pleasing to the subject.
mostly portraits are made within a cultural and artistic context with questions about the nature of identity, of representation, and of authenticity. the final result depends a lot of collaboration between the subject and the photographer.
it is characteristic of photography that, being understood in terms of casual relation to its subject, it is thought of as revealing something momentary about its subject – how the subject looked at a particular moment. and the sense of the moment is seldom lost in photography….
i would say that portraiture aims to capture the sense of time and to represent its subject as extended in time.