A narrow opening, hole, slit, or aperture, typically with one or more sides. A slot in a machine or container into which coins can be dropped to make it work; also, the position in which something is placed. He dropped the coin into the slot and dialled. A space or time in a schedule or program for an activity, such as an appointment or flight: Visitors can book a slot a week or more in advance.
In computer gaming, a location on the virtual reels where symbols will land when a slot is played. Slots are based on an algorithm that generates a number for each spin, which determines how much the player wins and whether the winnings come in big or small chunks. Slot machines are calibrated to pay back less money than the player puts in (over all), which is how casinos make their profits.
Contrary to popular belief, slots can be beaten if the conditions are right, but it takes a lot of math and logical loopholes to do so. Advantage play is the term for this, and while casinos frown upon it, professional gamblers have made millions of dollars using methods like edge sorting and counting cards. The same principles apply to slot machines, though. As the computer generates a random number each time a reel is spun, this determines how much and how often a symbol will land, and whether it will be on a pay line or not.