What is the difference between postmodernism and postmodernity?

What is the difference between postmodernism and postmodernity?

Not entirely sure, but the difference in the uses of the word "Modernism" and "modernity" is that this "ism" refers to the "artistic movement" while the "ity" refers to any aspect of life in the "modern world". I'm guessing the same is true with the "post-" prefix.

The reason I put "artistic movement" in quotation marks is because it is arguable as to whether or not "modernism" (and therefore by default "postmodernism") can be defined as "artistic movements", as they encompass such a vast range of different "sub-movements" that don't necessarily add up to an objective whole (compare, for example, Cubism to Socialist Realism- both examples of modernist artistic movements but extremely diverse in the nature of the works they encompass).

An "sm" and a "ty."

Dunno, but good luck on your exams!

Sometimes-- not always-- the terms are interchangeable.

A quick plug-in to the Google machine yielded many websites which could help you with your schoolwork.

http://en.wikipedia.org/wiki/Postmodernity
^ that webpage contains the contrasting definitions you asked for:

"Whereas postmodernity is a condition or a state of being associated with changes to institutions and conditions (Giddens, 1990) and with social and political results and innovations, globally but especially in the West since the 1960s, postmodernism is an aesthetic, literary, political or social philosophy, the "cultural and intellectual phenomenon", especially since the 1920s' new movements in the arts."

When I think of "postmodern" novels, I think of the elements we find there: a joking, aloof "distance" from the author, self-referential elements, parodies of existing styles, a jaundiced view of authority and dogmatic truth, etc. This first website is a PDF but has much useful
information:

http://www.scribd.com/doc/36257655/P...ern-Literature

This one isn't as cut-and-dried:
http://vc.ws.edu/engl2265/unit4/Modernism/all.htm

This one has a more generalized view of P-modernism, not limited to literature, which may be the "postmodernity":
http://www.associatedcontent.com/art...teristics.html

Post-modernity as it is used refers to a split in consciousness from modernity, post-modernism refers to the result that split has on art.