Since its first release, the most critical element in Entity Framework has been the ObjectContext. It is this class that allows us to interact with a database using a conceptual model. The context lets us express and execute queries, track changes to objects and persist those changes back to the database. The ObjectContext class interacts with other important Entity Framework classes such as the ObjectSet, which enables set operations on our entities in memory, and ObjectQuery, which is the brains behind executing queries. All of these classes are replete with features and functionality—some of it complex and much of it only necessary for special cases. After two iterations of Entity Framework (in .NET 3.5 SP1 and .NET 4) it was clear that developers were most commonly using a subset of the features, and unfortunately, some of the tasks we needed to do most frequently were difficult to discover and code.