A slot is a dynamic placeholder that either waits for content to be fed into it (a passive slot) or that calls out for content to be delivered to it (an active slot). It acts in tandem with scenarios and renderers to deliver content to the page.
A narrow depression, notch, groove, or aperture, especially one for receiving something, as a coin or letter. Also: a position or time of day; an allocated time on a schedule or sequence. I had an appointment at 2 p.m., so I scheduled my haircut for that slot.
The slot of a game is defined and managed using the ACC. Like renderers, slots are designed for one type of content only — you cannot feed different types of content into the same slot. It is not recommended that you use more than one scenario for offer management panels because this could result in unpredictable behavior if the contents of the slots change during runtime.
The first mechanical slot machines were developed in the 19th century by Sittman and Pitt. These early machines used five drums with a total of 50 symbols, and winning was achieved by lining up poker hands on the payline. In the 1980s, electronic slot technology allowed manufacturers to program slots to weight particular symbols. This increased the odds of certain symbols appearing on the payline and made them easier to win. The invention of touch-screen technology has also allowed for greater variations in slot functionality.