All businesses need to make money. Our Front Row Video database uses a simple business model for the rental prices: new movies cost more, old movies cost less.   Where should this data be stored? The Rental Prices will be stored in a Table: tblRentalPrices.   How will the rental price data be used with the movies? There has to be a Field in tblMovies that matches one in the tblRentalPrices so the two Tables can be joined, or linked. There has to be at least one Field in both Tables to create a relationship.   Tables are related by Key Data. The Primary Key is the best Field because it is unique: It is an AutoNumber that is Indexed (no duplicates). In contrast, last names are not unique: there are many, many customers with the same name. Microsoft Access 2010: Example of a Table with a Primary Key, MovieID, as well as a Foreign Key, RentalPriceID Relating Tables in a Relational Database Microsoft Access 2010: Example of the prompt when Access finds matching Keys, but does not detect a relationship between the Fields.