Realism describes a quality of painting, film, literature or other artistic medium that strives to present things as they actually are. It also describes a form of abstract philosophy that often informs such works.
Accuracy
Realism strives for absolute accuracy in the depiction of its subjects, devoid of any unnecessary dramatics or artistic affectation. Realistic works refrain from undue embellishment, aiming for a natural (as opposed to an artificial) tone.
Honesty
Realism seeks the depiction of honesty, rather than hiding things behind distortions or opinions. Unpleasant facts or images are presented as they are, as are plain or unassuming details about the subject.
Independence
Philosophical realism stresses the independence of objects from their observer. They have a life and an existence separate from anything else, which will continue regardless of anyone's thoughts on the matter.
Ordinariness
The subjects of realistic works are defined not by their exceptional nature, but by how ordinary they are. Shopkeepers are emphasized over military generals, for example, or streetlamps over grandiose mountains.
Difficulties
Realistic protagonists are often beset by great forces beyond their control--the natural world, for instance, or the indifference of a larger society--and in many cases they do not triumph in their struggle. Unhappy endings aren't universal in realistic stories, but they are fairly common, while happy endings often entail compromise and pyrrhic victories.
