A Track and field event. (Formerly called the "broad jump")
Competitors sprint down a runway (at elite level, usually coated with the same rubberised surface as running tracks), jump as far as they can off a slightly raised wooden board into a pit filled with fine gravel. The minimum distance from the board to the indentation made by the competitor in the gravel is measured. If the competitor starts their leap with any part of their foot in front of the board (a layer of plasticine is placed immediately in front of the board to detect this occurrence) the jump is declared illegal and no distance is recorded.
The exact format of the competition varies, but generally each competitor will get a number of attempts to make their longest jump, and only their longest legal jump counts towards the results. The competitor with the longest legal jump at the end of competition is declared the winner.
Speed in the runup and a high leap off the board are the fundamentals of success at the discipline, and it is unsurprising that many sprinters, notably including Carl Lewis, also compete successfully in the long jump.
The long jump has been part of Olympic competition since the inception of the Games. The long jump is also notable for one of the longest-standing world records in any track and field event, with Bob Beamon leaping 8.90 metres at the 1968 Mexico City Olympics, a jump not exceeded for 23 years.