I'm not going to add anything to the excellent comments by Kencelot and Eagle. One thing that many people find confusing is what constituted a British Para during WW2. Virtually all arms, Royal Artillery, RAOC, RAMC, REME etc, contributed units to the parachute divisions. This meant that the personnel in Artillery for example, maintained their speciality but cross-trained as Airborne troops. Basically an Airborne division was composed of the following elements:
Two Parachute Brigades (air-dropped)
One Airlanding Brigade (Glider-borne)
three artillery regiments (Glider-borne) Anti-tank, Light Artillery and Light AA.
three RASC (Royal Army Service Corps) Light Companies
Four RE (Royal Engineers) units, comprising 2 parachute squadrons, 1 field company and 1 Field Park company.
One RAOC (Royal Armoured Ordnance Corps) Divisional Field Park
One (REME) Royal Electrical and Mechanical Engineers Divisional workshop
Three RAMC (Royal Armoured Medical Corps) units, 2 parachute field ambulance and one (glider-landed) field ambulance.
In total, 12,416 Officers and other ranks. Artillery was composed of 23 20mm cannon (Polstein), 27 75mm pack howitzers, 84 6lb AT guns and 16 17lb AT guns...
So in summary, regiments supplied units for the 2 airborne divisions, the 1st airborne was deployed to Arnhem, the 6th in Normandy and the Rhine Crossing in April 1945.
If anyone needs information on Organisation, weaponry or uniforms, can I strongly suggest they buy the two volumes of Histoire and Collections (The British Soldier 1944-45) both of which are indispensable and available from Amazon UK.... Jim