If you’ve ever flown on a plane and been delayed because they’re waiting for a slot to open, you know how frustrating it can be. But did you know there are ways to minimize this kind of delay and get the air travel experience you want?

The word slot means a narrow notch or groove, especially one for receiving something, such as a coin in a vending machine. The term may also refer to a position in a group, series, or sequence, or an assignment or job opening. It is also used as a verb, meaning to put into or assign to a slot; to fit something in place.

In computing, a slot is a dynamic placeholder that either waits for content to be added to it (a passive slot) or calls out for content to be added to it using a scenario action or targeter (an active slot). Slots and scenarios work in tandem to deliver content to pages; renderers specify the way the content will be presented within the slot.

Charles Fey’s version of a slot machine was designed to be more user-friendly than the Sittman and Pitt invention that had been on the market at the time. His machine allowed players to choose from a variety of symbols, including hearts, diamonds, horseshoes, spades, and Liberty Bells. When three aligned Liberty Bells popped up, the player won a jackpot that could reach into the six-figure range. Unlike modern slot machines, however, the Liberty Bells didn’t actually land on any payline; the winning combinations were determined by the random number generator that was running the machine.