Cubism: http://en.wikipedia.org/wiki/Cubism
Pablo Piccaso: http://en.wikipedia.org/wiki/Pablo_Picasso
Georges Braque: http://en.wikipedia.org/wiki/Georges_Braque
Early Cubism (1908-1910): simplification and geometricization of form. In the early stage there is still a color differentiation between the figure and the background.

Pablo Picasso
House in the garden, 1908
Oil on canvas
73 x 61 cm
Pushkin Museum of Fine Art, Moscow, Russia

Georges Braque
Violin and Pitcher, 1910
Oil on canvas
46 x 28 3/4 (117 x 73 cm)
Kunstmuseum Basel
B. Analytic Cubism (1911-1913): There is a complete breakdown of the subject figure. Images are characterized by neutral subject and neutral color. Musical instruments are often included with in the picture.

Georges Braque
The Portuguese, 1911
Oil on canvas
116.8 x 81 cm
Kunstmuseum Basel
C. Synthetic Cubism (1913-1922): New objects are made out of broken down images. Collage was invented in this cubistic phase.

Pablo Picasso
Man with a Hat, 1912
Pasted paper, charcoal, and ink
62.2 x 47.3 cm
The Museum of Modern Art

Pablo Picasso
Three Musicians, 1921
Oil on canvas
200.7 x 222.9 cm
The Museum of Modern Art