" MVC does not specifically mention this data access layer. It's common to think of an application as having three main layers: presentation (UI), domain,and data access . In MVC, the presentation layer is split into controller and view. The most important separation is between presentation and domain. The V/C split less so. Though MVC comes in different flavors, control flow generally works as follows: The user interacts with the user interface in some way (e. g. Korean Fashion Model, user presses a button) A controller contains the input part of the user interface. The controller accesses the model, possibly updating it in a way appropriate to the user's action (e. "

" The controller does not pass domain objects (the model) to the view although it might issue a command telling the view to update itself. The user interface waits for further user interactions, which begins the cycle anew. Benefits and liabilities Although widely used, MVC has both advantages and disadvantages compared to other design options, and individual circumstances should be used to choose the most appropriate design. We discuss some of those here. View instability vs. model stability If constructed correctly, models can enjoy a fair degree of stability (owing to the stability of the domain model), whereas user interface code usually undergoes frequent and sometimes dramatic change (typically because of usability problems, the need to support growing classes of users, or simply the need to keep the application looking "fresh"). Separating the view from the model makes the model more robust, because the developer is less likely to "break" the model while reworking the view. Russian Fashion Model Attempting to stitch these two worlds together in a hand coded method without architecture is very common, and results in the model object being polluted with knowledge of the interface, and vice-versa. This makes the code very inflexible and difficult to maintain. "