There’s nothing more frustrating than getting to the check-in counter at the airport, trudging through security and struggling with overhead bins just to find your seat on the plane only to hear that there are no seats available for your flight until a later slot. This is one of those occurrences where understanding the meaning behind the word “slot” can make the difference between an annoying delay and a smooth departure.
The most basic definition of the word slot is a narrow opening in a machine or container that you put coins into to make it work. But the term has been used to mean a number of things, including the time and place where something will take place. A slot in a schedule can be a time for an appointment, a place in a program or a position in a queue.
A slot is also a type of container in PostgreSQL that acts as a dynamic placeholder that either waits for content (a passive slot) or calls out for it from a scenario or targeter (an active slot). In turn, slots can be filled with various types of content, depending on the scenario or targeter that created them.
The first slots were invented in the 19th century by New York businessmen Sittman and Pitt, who built a contraption with five reels that paid out winning combinations by lining up poker symbols. Charles Fey improved on their creation by adding a third reel, replacing the poker symbols with diamonds, spades, horseshoes, hearts and Liberty Bells — and making it possible to win by aligning three of them. Today’s video slot machines have up to fifty different pay lines, giving players more chances to win and often offering games based on how the numbers add up.