The bridge pattern allows us to operate a two part system which translates an expression of the intent to do work into the actual work to be performed.  It accomplishes this by pairing two different parts of a system that are dependent on each other for accomplishing a given task.

When discussing the bridge pattern, though, we must be careful from the outset to distinguish between two part systems.  We are not interested in systems where half of the work is done by one member of the team and then the other team member takes over half way and finishes the task.  For example, we are not talking about a leer-jet/limousine teams or commercial-airliner/taxi combinations.  In these examples a tangible piece of work is done by the first team member and this is followed by tangible work done by the second team member.

The Bridge pattern, instead, looks at situations where the two team members work hand-in-hand in order to accomplish the task.  So we are interested here in things like printer/cartridge, sim-card/Cell-phone, Limousine/Chauffeur, Mother/Father, Rim/Tire combinations.  Nothing at all can be accomplished without the member on the left-side of the slash.  Neither can the member on the right-side do anything by itself.  Without one or the other you cannot begin to do anything at all.  None can start the job for the other to finish; they are both powerless without each other.