Cubism was an early 20th century avant-garde art movement that revolutionized European painting and sculpture. Pioneered by Pablo Picasso and Georges Braque, Cubism was characterized by the geometric fragmentation and multiple perspectives of subjects. It emphasized two-dimensionality and depicted objects from various angles simultaneously on a canvas. Cubism had two phases - Analytic Cubism from 1907-1911 focused on reducing forms to geometric structures, while Synthetic Cubism from 1912 incorporated additional materials like collage. The movement influenced related developments in music, literature and architecture.