Cardan shaft -refers to a drive shaft in either a split propeller shaft with a centre hanger bearing or a full length shaft from gearbox to diff. It has a universal at one end minimum but usually have two.
Propeller shaft - A shaft to propel a vehicle. Read description above for Cardan shaft.
Universal shaft - A shaft to propel a vehicle. Read above descriptions
Universal Coupling - This is a cross or CV joint which has a flange as one half and is most often seen as the rear joint to a diff pinion flange on the end of the propellor shaft. It enables the driveshaft to be removed.
As you would have gathered; a Cardan shaft, Propeller shaft, Universal shaft and Drive shaft (one you did not mention) are the same thing. Which term you use depends on which school, apprenticeship country you are schooled in.
