A slot is a narrow opening into which something can be fitted. It is often used to hold a key or button in a machine. A slot is also a position in a list, a timetable, or a game board. The sense of “a gap or vacancy into which someone can fit” is attested from 1888 (slot machine, one operated by inserting a coin in a slot). Other uses include the space in the middle of a copy desk at a newspaper (attested from 1917) and the place where a person works or has a job (attested from 1942).
When playing slots it’s important to know what the pay table for the game you are playing looks like. This can help you understand how the different combinations of symbols will pay and what they need to do to trigger bonus features if the game has any. Usually a pay table will be listed on the screen of the machine, or embedded within the help menu in the case of video slots.
It’s also worth remembering that the outcome of any spin at a slot is completely random. It’s easy to fall into the trap of thinking that a machine must be due for a payout but this is never true. The random number generator (RNG) determines which combinations of symbols will land and when, so chasing a machine that you think is due to pay can lead to disappointment.