Mapper
An object that sets up a communication between two independent objects.
Sometimes you need to set up communications between two subsystems that still need to stay ignorant of each other. This may be because you can't modify them or you can but you don't want to create dependencies between the two or even between them and the isolating element.
for more details go to Chapter 18 of the online ebook at oreilly.com
This pattern is part of Patterns of Enterprise Application Architecture
05 March 2003