Similar to packaged subprograms, methods of the same type can be overloaded. That is, you can use similar name for various methods if their formal parameters differ in order, number, or datatype family. When you call one of the methods, the PL/SQL finds it by comparing the list of the real parameters with each list of the formal parameters.
You cannot overload 2 methods if their formal parameters differ only in parameter mode. Also, you cannot overload 2 member functions that differ only in return type