The key advantage of a geodatabase-the world's most advanced spatial object-oriented data model-is that it allows users to easily build intelligent models of spatial systems. This introduction to geodatabase concepts illustrates how to implement geographic designs by importing existing data or building a new geodatabase from scratch. Topics include migrating existing geographic data into a geodatabase; creating new feature classes and datasets; adding behavior to features by creating subtypes and validation rules; designing a geodatabase using Unified Modeling Language (UML); and creating schema using Computer-Aided Software Engineering (CASE). A tutorial provides an overview of creating and editing a geodatabase, and is followed by instructions for creating a first geodatabase.