My question is as follows:
Most non EU nationals need to submit a landing card to a UK Immigration officer upon arrival in the UK. You will need to specify on how long you will stay and your contact information. However What I do not understand how is it possible to keep a track record of these passengers, since when leaving the UK, you do not have to go through immigrations. Neither a Stamp or part of the Landing card is forwarded to immigrations (as in Japan and the US).
For example most countries will keep a track record in the immigration System, on how long someone stayed in a country, and not to overstay the permitted period.
In most Countries people will have to go through immigrations upon arrival and departure, Also in the US there is no Immigrations when leaving the country, however Airline staff will collect a part of the green landing card, and forward it to U.S immigrations.