Abstract expressionism is a post War II school of painting that originated in New York City. It is characterized by freely created abstractions that express emotion through non-traditional and (generally) non-representational means, thereby freeing the artist from the constraints of objective reality. This style of painting emerged as a reaction to the limitations of earlier styles such as Cubism and Surrealism, which many artists felt constricted their creativity.
The school is perhaps best exemplified by the work of Jackson Pollock, whose “drip paintings” revolutionized the use of color and paint application in modern art.