Realism in drama refers to closely representing truth in the observed facts of life. The characters derived from realism in drama are middle or lower class; the events of drama are ordinary and commonplace; the influences on the characters and actions are the external influences of social factors, as defined by social Darwinism. Realism was criticized for focusing too much on the influence of external reality at the expense of overlooking the influence of internal cognitive and psychological function. Realism also led to naturalism in drama.
Naturalism in drama, developed by the French, took realism further and made it give as close a representation of reality at the merchant, working and lower class levels of society as possible. This effort for pure realistic representation went so far as to involved revolutionizing set structure and acting technique, which was led by Stanislavski, as well as encompassing the strict incorporation of Darwinian social theory and scientific data.
There is a very clear article on realism at the Foreign Languages Institutes Fujian Normal University.