Question: i heard that domain driven design pattern but do not know what it is exactly. is it design pattern? if so then how it is different from mvc or mvp. please discuss this. how to implement domain driven design pattern with c#.

Answer: 
In short: It's not a design pattern. You can see it as **set of patterns** and **principles** where you write code that reflects real life objects and concepts in a specific domain (problem area):

From the StackOverflow tag:

> 
> Domain-driven design (DDD) is an
>  approach to developing software for
>  complex needs by deeply connecting the
>  implementation to an evolving model of
>  the core business concepts.
> 
> 
> 

Here is a link to study:

* [Wikipedia](http://en.wikipedia.org/wiki/Domain-driven_design)
For DDD in the C# world, please look at [Applying Domain-Driven Design and Patterns: With Examples in C# and .NET](https://rads.stackoverflow.com/amzn/click/com/0321268202) . Jimmy Nilsson (the author) is a recognised leader in DDD using a C# slant.