A slot is a narrow opening in something that allows it to fit into something else, such as a door handle or a computer keyboard. A slot can also be a position in a schedule or program, for example when someone books an appointment with a doctor, they may book a time slot that is a week or more in advance. If something slots into something else, it fits easily into that space. The car seat belt slid into the buckle easily.

A computer slot is an opening in a machine into which you can insert printed circuit boards. This is different from bays, which are sites in a computer into which you can install disk drives. Slots are not to be confused with expansion slots, which are additional locations within a computer into which you can install more than one type of board.

In ice hockey, the slot is the area of the rink between the face-off circles in the offensive zone. The area below the circles is called the low slot, while the area above them is known as the high slot.

In electromechanical slot machines, the mechanical reels were spun by a crank or handle that caused the coin to drop into the slot. Modern slot machines are driven by microprocessors, which assign a probability to each symbol on a reel and determine whether a winning combination occurs. The odds of a particular symbol are shown on the paytable, but they can vary slightly from machine to machine.