The Electronic Centralized Aircraft Monitoring System (ECAM) consists of two displays, the UPPER ECAM and the LOWER ECAM. During standard setup the upper ECAM shows the Engine Warning Display and the lower ECAM shows the System Display.
The Engine Warning Display (E/WD) shows the engine parameters, fuel and the position of the flaps / slats. Furthermore, it displays warning messages in the event of faults as well as corresponding procedures. "NO BLUE", all instructions shown in green, is an Airbus philosophy and means all systems are "healthy".
The System Display (SD) shows and verifies all systems of the aircraft. E.g. status of the doors (open/closed), temperature of the brakes, control devices and the temperature with in the aircraft. The Switching Panel switches between the displays.