Expressionism refers to the tendency for an artist to distort reality for emotional effect. It is a highly subjective art form. The term is generally used in reference to works made in the 20th Century but has also been utilized by many artists to create pieces which evoke strong emotions. It is a very subjective art form which is not necessarily aesthetically pleasing, although it can be. More important, however, is the transference of a deep emotion though the art work.
The distortion of reality in expressionist works is often accomplished with the use of visible brushwork and expressive, or unusual, color combinations. Other techniques, however, may also be incorporated.