In gambling, a slot is a position on the reels where a symbol can appear. The symbol that lands in this position determines whether you win or lose. In addition to the reels, a slot machine has a pay line that determines how much you can win. These components are controlled by a computer inside the machine. Modern machines are designed with a par sheet that specifies the weightings for each stop on the reel. This makes the odds and house edge of a slot game a known quantity for casino management. Unfortunately, many gambling companies keep these par sheets secret, so players have a hard time knowing exactly how much they are risking on each spin of the reels.

Slot can also refer to:

A slot on a computer motherboard, which connects to a CPU and may contain memory slots or other expansion slots. Often, slots are referred to by their I/O designation, such as ISA slot or PCI slot. Alternatively, the term can refer to a specific type of slot, such as an AGP or ATI graphics port.