A slot is an opening in a computer’s chassis that can accept expansion boards. A slot is not to be confused with a bay, which is the space inside a computer that is used for installing disk drives.

No one has uncovered the Platonic ideal of a slot machine, but there are some principles that undergird most games. For example, slots tend to be designed with a single theme and recognizable symbols. They also feature a kind of musical uniformity. Soundtracks are often in a major key, and the sounds of coins clinking together or a bell ringing are common. A few other common elements include color schemes that tend toward primary or pastel, franchise tie-ins, and a general sense of visual uniformity. In addition, slots are designed to appeal to a young generation of gamblers with pop culture imagery. Video monitors and 3D graphics are being used to make the machines more aesthetically appealing. This is a tactic designed to counteract the decline of older gamblers who are finding new forms of entertainment on their computers and mobile devices.