(slightly simplified, but along the general layout)
On the modern Boeings the two yokes are interconnected, thus move the same way. Force felt on one side is according to input force from the other. It is done by a so called drive back. This is a artificial replication of the force input to the ACEs (actuator control electronics) by the pilots.
The ACEs transmit the input to the PFCs (primary flight computers) who then process it and send it back to the ACEs who in turn actuate the hydraulics for the flight control surfaces.
If the input sensed by the PFCs exceeds the programmed parameters of the envelope or protection, the PFCs increase the necessary force up to not executing the commands. However, if the pilot then increases his own input force above a certain value, the PFCs give up and say: "You want it, you get it" and the input is routed directly to the ACEs for execution.
This latter function is the so called soft protection, as opposed to the hard protection of the Airbus that does not allow override of the protections. Only if 3 of the 5 Airbus computers (2 Prims and 1 Sec) are switched off from the overhead panel, the system goes into direct law and then allows unprocessed input.