Portraiture is the art of making pictures of people — the face, the look, sometimes the whole body — so that you feel you are meeting them. A portrait is one such picture; portraiture is the skill, the craft, and the long tradition of making them. Painters have done this for centuries with oil and pencil. Later, cameras joined in, so you will also hear photographic portraiture. The word sounds a little formal and old-fashioned. In a museum or an art class you might say “a course in portraiture”; in ordinary talk people usually say “portrait painting” or “taking portraits.” It is not landscape (land and sky) and not still life (objects on a table). You use it when you mean the art as a whole, not one frame on a wall.