What is the difference between World Literature, British Literature, and American literature?

The difference between American and British literature has a lot to do with the ages and stages of 'greatness' characterizing both. American literature hasn't been around for as long but has a wonderful frontier attitude. There's loads of adventures and coming of age stuff and some heavy fiddling around with conventions. British lit has it's roots in medieval stuff and, obviously, in Shakespeare. It can be pretentious but more often is characterized by either satire or poetic undertones.

American lit sometimes alludes to British (especially in the reactionary sense) but British rarely alludes to American. World Lit alludes to both but rarely in a complimentary manner.

You might go on to divide World Literature into Post-Colonial and Independent literature. Post-Colonial literature from around the world are works written after British world dominance. Some speak of exploitation while others speak of influence. Independent literature from around the world is characterized by the culture from which it springs with no more weight given to colonial powers than to any other event or background information. I'm a fan of Russian literature (in translation) which is only 'World Literature' if you happen to be outside of Russia.
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                                                                                   Shabnam khan