What is the difference between Expressionism and Cubism in art?

Pioneered by Pablo Picasso and Georges Braque in
France, Cubism was a revolution against figurative art. 
For them, the human figure became more a series of planes moving through space, more a
machine than a human.  For instance, Picasso's Nude in an Armchair,
as one critic writes, "reconciles non-literal representation with a voluptuous awareness
of the body's opulence."  The term cubism was first used by the
critic Vauxcelles for the geometric simplications of Barque's L'Estaque landscapes. 
Picasso's Ambroise Vollard is cobsidered the epitome of the
"analytical" phase of Cubism.  For, the sitter is presented from a variety of
viewpoints, thereby appearing fragmented into a crystalline structure of interlocking
plances.  Color variety and texture are sacrificed in Cubism and perpectival effects are
replaced by a shallow, ambiguous sense of space.  Cubism had as its aim not complete
abstraction; rather it was a new kind of realism, one that sought a balance between the
depiction of reality and the autonomy of the painting as a physical
object.

Like Cubism, Expressionism was a reaction to
realism, but rather than reducing objects to their geometric distinctions, Expressionism
characterizes 20th century north European art with its subjective stress on heightened
emotions and the artist's inner vision.  The term was first used to describe an
exhibition of Fauve and early Cubist paintings at the Berline Sezession.  As a reaction
against the realism and naturalism of the late 19th century, Expressionist artists
insisted on their emotional response to their subjects from which they derived the
concept that genuine artistic form develops from one's inner necessity.  Artistic form
could never be imposed by tradition or convention.  For this reason, the expressionists
could justify the use of any artistic means which gave expression to their feelings. 
These means include distortion, violent and evoctive color combinations, and eclectic
absorption of such diverse influences as medieval, folk, and tribal
art.