Do you mean the difference between say the Calvert 5 bar approach light system and the Barette Approach light pattern.
The former was developed at at secret place in southeast England near Farnboro' around the end of the war. I think the idea was to give alignment, roll and distance to go info.
The lights lead you to the touchdown point. The figure is in CAP168 somewhere.
The other system seen typically in the US and Europe presumably comes from the ICAO Visual Aids Panel of similar age as it is shown in Annex 14.
Hope this helps........... a bit
Sir George Cayley