Inversion of Control (IoC) pattern or Dependancy Injection (DI)

Using object-oriented design principles and features such as interface, inheritance, and polymorphism, the IoC pattern enables better software design that facilitates reuse, loose coupling , and easy testing of software components.

Def of DI: Instead creating an new object every time we call the container which will create the object of that class for us.

Injection or Imposing a Dependacy (called an object b or can be a Property, method also) on the De pendant class A through a container or IoC Framework is called DI.

Ref: http://www.dotnetspark.com/kb/266-inversion-control-ioc-and-dependency-injection.aspx

Ref : http://dotnetslackers.com/articles/aspnet/Building-a-StackOverflow-inspired-Knowledge-Exchange-Three-Tiers-to-MVC-Hooray-Dependency-Injection.aspx