This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I don't understand, how a object communicate with another object where both object from different class. I mean, how a object "a" created from class "X" will communicate with object "b" which created from class "Y".