In an organizational culture where substantial amount of data is assembled and accumulated every day, this paper explains how the advanced field of data mining can be used for extracting or \"Mining\" knowledge from large amounts of data. The application of this technology within an organization leads to great benefits and effective decision making. Data mining is the medium which explores promising and flourishing technique for data and information systems. This paper familiarizes data mining techniques and its applications. These techniques help in effective policy making and decision making for enormous accumulated data in an organization.