A slot is a dynamic placeholder that either waits for content (passive slot) or calls out for it via a scenario or targeter. It delivers the content to the page and is then displayed by a renderer. A slot can only contain one type of content, and it should only use one scenario to fill its contents. Using multiple scenarios to feed a slot can result in unpredictable results.

Slot definition: 1. a narrow notch, groove, or opening, as in a keyway or the slit for coins in a slot machine. 2. a position or place in a program or schedule: He slotted a meeting into his day. 3. a time when an activity can take place: We can go to the museum at that slot.

In a slot machine, players insert cash or, in “ticket-in, ticket-out” machines, paper tickets with barcodes into a designated slot on the machine. The machine then activates a series of reels that stop to rearrange symbols and, if a winning combination is formed, award credits according to a pay table. Most slots have a theme, with classic symbols such as fruits, bells, and stylized lucky sevens.

In the US, private ownership of a slot machine is legal in Alaska, Arizona, Arkansas, Indiana, Iowa, Kansas, Maryland, Montana, Nevada, New Mexico, North Dakota, Oklahoma, South Carolina, Utah, and West Virginia. Some states prohibit the sale of certain types of slot machines, while others require that machines be regulated by state gambling authorities. Many casinos offer a variety of slots. Some are progressive, while others are fixed and have predetermined pay lines.