Ever since "widescreens" became popular, I allus wondered how do it know?
Just curious...
There appears to be a standard protocol by which the computer can query the monitor for manufacturer and model number. If the monitor's in the computer's database, it con then install and configure the appropriate driver. (I've had a couple of cases of monitors NOT in the database -- my current monitor was not IDed in the previous version of Kubuntu I ran, but the latest set it up and ran right away.)