What is Data Mining?

Data Mining is the process of finding new and potentially useful knowledge from data.

A simpler definition is:
Data Mining is the art and science of finding interesting and useful patterns in data.

See a basic introductory article "From Data Mining to Knowledge Discovery in Databases", U. Fayyad, G. Piatetsky-Shapiro, and P. Smyth, AI Magazine 1996.

See also many other publications under www.kdnuggets.com/publications