What is the difference between long stay and short stay parking at the airport?
Short-term parking is for vehicles that need to park at the airport for less than 24 hours. Long-term parking is for vehicles that need parking for the complete duration of their trip and require at least one or more overnight stays.
Typically, you can park your car at the airport for up to a month. Some airports can accommodate longer stays, but special arrangements may be required. JFK Airport, for example, asks travelers who require parking for more than 30 days to contact ABM (airport services) on the day they arrive.
For anyone who books in advance, the maximum length of stay at Heathrow Short Stay Parking Terminal 2 is 99 days. If you just turn up on the day without pre-booking, you can stay as long as you like, you'll just continue to pay the roll-up daily tariff.
In theory the car park operator can charge you for extra time your car is in the car park, however, many car parks will in fact allow for a 'courtesy period' to allow for delays, meaning you will not be charged extra.
Size and proximity alone make the land expensive. Much of the space airports use is dead space in terms of generating revenue - the grass verges, taxiways, and roads. But much of this revenue dead space costs money to build and maintain. This burden falls on the two big users of airports - airlines and passengers.