A slit or other narrow opening, especially one for receiving something, as a coin or a letter.

In computing, a slot is a space on a motherboard for expansion cards, such as an ISA (Industry Standard Architecture), PCI (peripheral component interconnect), or AGP (accelerated graphics port) slot. It may also refer to a memory slot on a computer.

Unlike many other casino games, slots are designed to pay back less money to players than they take in, and this is how casinos make their profits. However, there are some benefits to playing slots that should not be overlooked, including the fact that winning a slot machine triggers a chemical change in the brain, which releases endorphins and leptin, which are responsible for feelings of happiness and satisfaction.

A slot is a dynamic placeholder that either waits for content to be added to it (passive slot) or calls out for content from another source (active slot). Slots and scenarios work together to deliver pages on a website; renderers specify the presentation of the slots’ contents.