Realism is the precise, detailed and accurate representation in art of the visual appearance of scenes and objects i.e., it is drawn in photographic precision. Realism in this sense is also called naturalism, mimesis or illusionism. Realistic art was created in many periods, and it is in large part a matter of technique and training, and the avoidance of stylization.
“Realism (arts),” Wikipedia, accessed August 12, 2016, https://en.wikipedia.org/wiki/Realism_%28arts%29.