What Is The Use Of Overloading In Polymorphism?

Overloading have no connection with polymorphism rather its Object oriented concept. Overriding is a concept in Polymorphism where each object in the hierarchy can override a parent class method. By dynamic binding this overridden  method is bound to caller object at run time and actual object is used to call the function. This is how polymorphism (many faced) paradigm works.

Overloading by definition: You can have as many methods with same name as you need as long as their parameter list is different.