A slot (plural: slots) is an aperture or groove, usually narrow and deep, used for insertion of an object. A slot can also be a device that holds something in place, as a lever, pulley, or bracket. In computing, a slot is an area on a computer motherboard that can hold an expansion card (e.g. ISA, PCI, AGP).
The first video slots were invented in las vegas in 1976. They were changed a bit to prevent cheating and were approved by the gaming commission. These machines are highly mechanized and use a number of reels with different stops on them to create combinations. When the reels stop the games typically show you the winning lines.
Until the 1990s it was common for gamblers to drop coins into slots, but the advent of bill validators and credit meters allowed them to simply insert paper bills for each spin. This meant that slot machines could pay out small amounts frequently enough to keep gamblers seated and betting, a strategy called taste.
In hockey the slot is a position in front of the net that provides the best chance to score without deflections. There are two positions considered the slot: the low slot and the high slot. The low slot is directly in front of the goaltender and between the face-off circles, while the high slot is above them. Defensemen often try to establish the high slot as no man’s land by laying out big hits to wingers and centers trying to skate through it.