This document discusses data mining and knowledge discovery. It begins by describing how the rise of information technology has led to vast amounts of data being collected from various sources like business transactions, scientific experiments, medical records, videos, satellite images, games, digital media, software projects, and the web. It then discusses how data mining aims to extract useful patterns and knowledge from these large databases to help with decision making using techniques like classification, clustering, association rule mining etc. Finally, it provides a diagram depicting data mining as one step in the broader iterative knowledge discovery process.