"FMS combines data from various aircraft systems, which are fed into a central computer, to manage route naviagtion and aircraft performance.
The main section of the FMS is the flight management computer systems (FMC) which is a dual system using two flight management computers and two CDU's. CDU's are a single point to control for the crew to access FMC. Via CDU crew can initiate and control flight plan navigation and performance management and monitor its execution"
Would i be right in saying that the FMS is just basically the inner working of the FMC and that the CDU's are the screens on the FMC? as this would then make the CDU's and the FMC'S the singe point to control for the crew