According to Sun and Msdn it is a design pattern.
According to Wikipedia it is an architectural pattern
In comparison to design patterns, arch
I know that it's been answered awhile ago, but no one has yet mentioned the book that made MVC famous: Pattern-Oriented Software Architecture (POSA), by Buschmann, et al published in 1996. Though not as widely read as the Design Patterns book, by Gamma, et al, POSA is one of the foundational books used by the patterns community.
Oh, and POSA very clearly identifies MVC as an architectural pattern. My hunch is that MS and Sun are just being sloppy and calling every pattern a "design pattern".
The design patterns inside the Model/View/Controller (MVC) triad of classes include and may not be limited to:
Observer, decoupling objects so that changes to one (the model) can affect any number of others (the views) without requiring the changed object (the model) to know details of the others (the views).
Composite, which lets us treat a group object (a composite view) just like we treat one of its individual objects (view components).
Strategy, where a view uses an instance of a Controller subclass to implement a particular response strategy; to implement a different strategy, simply replace the instance with a different kind of controller.
Factory Method, specifying the default controller class for a view.
Decorator, adding scrolling to a view.
Reference
Eric Gamma, Richard Helm, Ralph Johnson, and John Vlissides. Design Patterns: Elements of Reusable Object-Oriented Software. Addison-Wesley, Reading, MA, 1994.
Design patterns say how to write code effectively (considering Code Metrics).
A few benefits:
Architectural patterns say how to utilize resources effectively.
In MVC, a). Views can be created using javascript templates and also html can be used b). Controllers can be written .NET framework and c). Models can be written in Java - a java service may be used that returns only json data.
While in design pattern, a pattern can't be implemented in which code can be written in multiple technologies like AdminUser class in Java, Customer class in C#, Partners class in Php and a factory pattern in Ruby :); hmmm..so easy?:)
I think both are true. If you're looking at a particular instantiation of MVC in a framework like Ruby on Rails, that instantiation is more of a design pattern. If you look at MVC as a general concept, it's more of an architectural pattern.