A European artistic faction in the first decades of the 20th century, prevalent in Germany (German Expressionism). Ranging from painting (e.g. Edward Munch) to literature (e.g. Gottfried Benn) to theatre (e.g. Georg Kaiser) and back ... The view on reality is coupled with the strong expression of the own feelings of the artist. For me, expressionism is defined mostly by the usage of sharp contrasts - language that is breaking with the rules of grammar and tends to be exclamatory (but also highly metaphorically), the usage of strong color differences in the paintings, and so on.
Other artistic factions in roughly the same timespace include dadaism, surrealism and futurism.