Ending an abstract class with a hyphen "-" is purely a design decision. There is no technical advantage for doing this. @baseclass is not intended to be instantiated and therefore is created as an abstract class for the purpose of creating reusable rules that is applicable to all classes created in Pega. 

Hello Chuat,

Actually i am owrking on java technology, it would be greate helpful if you explain this compring any programing language...as you said @baseclass is for creating reusability rules..without creating object how do we reuse the rules...?

In Java, all classes will ultimately inherit the Object class. In Pega, all classes will ultimately inherit the @baseclass class.

In java we can create object to Object Class. Here as you said we can't create right?

Yes, you are unable to instantiate an @baseclass class.