What, exactly, is Inversion of Control? Most commonly used in reference to Dependency Injection or Dependency Inversion (the D of SOLID). Inversion of Control is a programming methodology where objects are given information about other objects in the system without having to create or control them. This is mostly done with either abstractions or interfaces (again the D of SOLID).
As you will see in this video, we begin with a simple procedural example and begin looking at how we change who creates the Data-access layer and how the User class knows about it.
All of this is done with the desired end goal of keeping the functionality of a class limited to only what the class should be doing.
http://en.wikipedia.org/wiki/Inversion_of_control
http://joelabrahamsson.com/inversion-of-control-an-introduction-with-examples-in-net/
http://www.codeproject.com/Articles/592372/Dependency-Injection-DI-vs-Inversion-of-Control-IO
http://en.wikipedia.org/wiki/Solid_(object-oriented_design%29
