This textbook is for the IDMA 201 course in the IDMA Associate Insurance Data Manager (AIDM) designation program. This course defines data management, describes the functions of data managers, provides the business case for data management and introduces the student to concepts and tools used by data managers. Whether you are an actuary, a claims professional, business analyst, or almost any of the other key functions, knowledge of data management can help you do your job better and help you prepare, understand, and protect the raw material -- the data -- so critical to your organisation. IDMA courses, workshops, and forums are highly recommended for a broad audience including new hires, IT and data modeling professionals who want to broaden their knowledge of the business side of insurance data management, anyone who manages and governs data in the industry (statistical, or management information data), and anyone who needs to use or communicate good quality data/information -- from actuaries to underwriters, and claims and analytics professionals. Students who complete the four IDMA-developed courses and successfully pass the examinations are awarded an Associate Insurance Data Manager (AIDM) designation. The IDMA courses may be taken in any order; there are no prerequisites. However, the courses are numbered to indicate a recommended sequence. For details on the designation requirements, please refer to the IDMA Website at www.IDMA.org.