Check out the wikipedia page on Humanism for a kind-of-complete history, but in a nutshell it is an art form that centers on humanity's importance in the real world. Society and the purpose of people in their imediate world is a main factor. Examples may consist of people or individuals performing mundane tasks with emphasis on the figure and emotional state of the people. In terms of the craftmanship, it varies from realism to a more expressionistic form. Emphasis is key as a design principal.