http://en.wikipedia.org/wiki/Topology:

Topology (from the Greek τόπος, “place”, and λόγος, “study”) is a major area of mathematics concerned with spatial properties that are preserved under continuous deformations of objects, such as deformations that involve stretching, but no tearing or gluing. It emerged through the development of concepts from geometry and set theory, such as space, dimension, and transformation.

I hope that didn’t help xD otherwise I’d say you’re a geek

Topology is the way you construct your mesh. Major thumb lines of topology are to not use triangles and only rarely poles (vertices with more or less than 4 edges) . However, bad topology can also be a very uneven spacing between the vertices or a too even one (sometimes you have to have dense parts and loose parts, such as with joints, where the inner part is supposed to be dense to preserve volume.

Did that help you?