dotnet tutorials: what is the difference between asp.net and mvc

If a 3-tier design were like this:

Client <-> Middle <-> Data

the MVC patter would be:

     Middle
     ^    |
     |    v
Client <- Data

Meaning that:

in the 3-tier equivalent, communication between layers is bi-directional and always passes through the Middle tier
in the MVC equivalent the communication is in unidirectional; we could say that each "layer" is updated by the one at the left and, in turn, updates the one at the right –where "left" and "right" are merely illustrative

P.S. Client would be the View and Middle the Controller

for more reference about the mvc
http://weblogs.asp.net/scottgu/archive/2007/11/13/asp-net-mvc-framework-part-1.aspx

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