Parameter Overiiding in SV

what is Parameter Overriding Concept in SV?
I know that when we are using define WIDTH 16(declared outside of Module) we need to use WIDTH to access that width value & by using Parameter is parameter WIDTH 16(declared inside the module)to access this we need to use WIDTH. I understand this concept but by using “parameter” there is parameter overriding is there what it means?can anybody explain it?
thanks
Balaji.

The section on parameters of my DVCon paper: Using Parameterized Classes and Factories: The Yin and Yang of Object-Oriented Verification explains the difference between text macros and parameters.