Biztalk PortType, Port, Operation == Class, Instance, Methods

I have seen many people creating New PortTypes for every Port even if they are of the same data type.

So I am giving a simple correlation between OOPs Classes and Biztalk PortTypes.

Class (Similar To) PortTypes - Just defines Oneway or TwoWay

Instance (Similar To) Ports - Defines Send or Receive direction, Binding Type

Methods (Similar To) Operations  - Defines the operation on the port,