The Model layer represents your data structures and business logic. It is the domain-specific representation of the information that the application operates on. Many applications also use a persistent storage mechanism (such as a database) to store and retrieve data. MVC does not specifically mention the data access layer because it is understood to be underneath or encapsulated by the Model Layer. This is the most important part of your application and it is usually modeled by ColdFusion components (CFCs). You can even create the entire model layer in another language or physical location (Java, web services).