Can somebody please help in understanding the difference between pressure compensated variable displacement pump circuit and load sense? Below is my understanding:

VD Pressure compensated Pump circuit: You can not control flow rate unless the pressure compensator pressure setting is achieved. After which pump flow can be controlled while pump maintaining that maximum pressure.

Load Sense Pump Circuit: Firstly, We can control flow rate by regulating needle valve or proportional valve that is downstream of pump to get required actuator speed without reaching maximum pressure compensator setting. Secondly as the load changes the pump adjusts valve upstream pressure to maintain the flowrate across the valve (which we adjusted before to get required actuator speed).

Is my understanding right? Kindly explain in simple terms if you can. Thank you in advance