The cabin altitude is the pressure maintained in the cabin of a commercial airliner at cruising speed corresponding to a certain altitude. It is determined to ensure the best passenger comfort whilst taking into account the structure of the aircraft. A typical commercial aircraft flies at about 35,000 feet (10,700 metres), but the pressure inside the cabin (or cabin altitude) is between 6,000 and 8,000 feet (1,800 and 2,400 metres) depending on the age of the aircraft.
As every week, we went to put the question to a number of passengers in an airport. It is definitely not the pressure at the ground level.
On the same theme, you can also look at other previous videos such as: Altitude versus cabin altitude, or At what altitude is the the cabin of an airplane pressurized?