The hole in the back is for engine run-ups and testing as some have correctly surmised above. On the US carriers the lifts are ‘normally’ (depends upon the carrier obviously) two on the starboard side fore and aft of the superstructure and one, sometimes two on the port side.
The issue being that the angled deck is obviously on the port side and the operation of the port lift would affect launch and recovery slowing the deck rotation.
Aircraft are launched using one of up to 4 steam catapults, two on the waist and two on the foredeck. The foredeck cats are angled very slightly apart on the newer Carriers to launch the aircraft to the left and right of the ships track just in case of a cat shot failure, engine failure or ejection. This gives the flight crew a fighting chance of not being steam rollered by the ship after an ejection!
Recovery is normally done by pilots talking to area control when they are outside of the CCZ (carrier control zone) which is normally a 5nm radius circle centered on the ship to gain permission for entry to the CCZ and circuit placement or stack join.
Once inside they will be transferred to ‘flyco’ (not sure of the modern day callsign I’m afraid, it’s been a while!) for circuit position, landing number, parking position etc. You will also be in contact with ‘paddles’, a squadron pilot who is in the tower at all times during recovery in order to assist with any technical issues (it’s difficult to read the manual with a failure and land on a pitching, rolling, heaving deck!)
The aim is to fly a fixed AOA approach using pitch and power to control speed and height respectively. You use the Carrier Lineup Beacons on the port side to judge your glide path, keeping the central ‘ball’ between the green horizontals all the way to the deck, aiming for the 2nd to 3rd wire giving you about 20 feet over the rollback (the rounded edge of the flight deck over the stern). Keep a constant AOA (keeps the hook head and the mains in a level plane) over the stern and adjust height with power, once you hit the deck apply full power and re-heat in the event of a bolter. As you get the decel of the cable (and boy do you get the decel!) select idle and apply the brakes, look for the flight deck handler who will signal to release the brakes and the cable will pull you back and disengage from the hook.
Raise the hook, fold the wings and follow the marshallers signals to the shut down position.
Simples. ;)
Edited to add the shirts denote different roles on the flight deck. I can’t remember them all I’m afraid but a quick google lookup should suffice! Badgers, pinkies, greenies, loaders etc…