These may differ slightly from machine to machine, as monitors have changed over the years to use more touchscreen controls and less physical buttons/dials. There are usually two screens: one that focuses on telemetry (sensors/monitors) and one that focuses on the ventilator and gas settings. On very old machines, there may only be one big screen, with a much tinier screen for controlling the ventilator.
There is also a separate screen for a desktop computer that runs the anesthesia charting software.