There are many different ways that the art world can be divided but one certainly is between realists and the avant-garde (whatever that means these days).  The gulf between these camps is often unbridgeable; the avant-garde still tends to view realism as reactionary, and many realists respond by dismissing almost everything done after Post-Impressionism.  I have always thought this state of affairs lamentable because at their root both impulses are essential to a healthy tradition.  If I can summarize--realism is essentially the impulse to directly study the appearance of our world and render it with some degree of fidelity.  The avant-garde sees the primary source of art in the mind and embraces a radical freedom for artists to go wherever their minds beckon.  Realism holds that our visual world is the primary source for form (and ideas) and the avant-garde holds that ideas (and forms) emerge most directly from human cognition, individual and collective.  

And to that I say, yes and yes!!  What is more, these emphases can correct the narrower tendencies of both traditions.  Much realism practiced today is mindless--pretty pictures of pretty places--it needs a strong dose of intellect to say something deeper.  And much avant-garde work is solipsistic and, often, just plain boring--it needs to continually measure itself against the depth of the larger world that is out there.  Why can we not have Andrew Wyeth and Marcel Duchamp and have them talking to each other.  Until we do, the art of both camps, both houses will be unnecessarily diminished.