use fo base keyword for a parent class method in derived cls

In inheritance incase of a 2 parameterised constructors present in both child and parent .. Just inorder to access child class data members , parent class constructor should be accessable to child class :) .. One of the rule of constructor 

So we use chaining mechanism for communication .. like we pass values to parents constructor using BASE(x,y) like that

Base always refers to Parent .. This contray refers to current class .

Regards

Check the below thread, it may answer your query:
http://stackoverflow.com/questions/2644316/what-really-is-the-purpose-of-base-keyword-in-c