Beginners guide to Altitude, QNH, QFE, and Transition Altitudes in Microsoft Flight Simulator

A very quick guide to altitude, QNH, QFE, Transition Altitudes, Transition Layers, and Transition Levels in Microsoft Flight Simulator (or any simulator for that matter).

Disclaimer - I'm not a professional pilot, tutor, teacher of aeronautics, neither do I hold an qualifications in these fields. This is purely based on my own reading, and learning along the way.