This is a nice quote by Stefano in his blog (link here). I thought it’s interesting to Quote here.

 
An object-oriented framework is a (generative) architecture designed for maximum reuse, represented as a collective set of abstract and concrete classes; encapsulated potential behavior for sub-classed specializations.
The major difference between an object-oriented framework and a class library is that the framework calls the application code. Normally the application code calls the class library. This inversion of control is sometimes named the Hollywood principle: “Do not call us, we call You”.