" Domain logic adds meaning to raw data e. g . calculating if today is the user's birthday or the totals, taxes and shipping charges for shopping cart items. View: This renders the model into a form suitable for interaction, typically a user interface element. MVC is often seen in web apps: the view is the html page and the code which gathers dynamic data for the page. Controller: This responds to events, typically user actions, and invokes changes on the model (but *not* the view). Many applications use a persistent storage mechanism (such as a database) to store data. Battle Star Galactica Ship Model 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. "

" That is the case when a consensual understanding of these concepts has been achieved or can be achieved by means of definition, examples, etc. With respect to what is shown by a conceptual model there are differences at least with respect to computer science, mathematics and logic. Mathematical models in one way or another establish a functional cohesion between entities such as input values and output values. Logical models establish an interpretation relationship between formulae and structures. Models in Computer Science are largely organizational in that they show how data, a cooperation between agents, the process of creating a response to an external stimulus, an algorithm, or similar is structured. The emphasis of organization that is apparent in many models of computer science appears to be a consequence of either of the following: (1) complexity issues need to be dealt with such that a functional cohesion actually can be evaluated. (2) a domain of individuals or universe of discourse has to be established and the individuals within that domain are supposed to be capable of being distinguished from each other by means of their condition in that organization or particular handles available to a user of that model. French Model Napoleonic Ship III. The original of a model may itself be physical or conceptual. "