A slot is an authorization to take-off or land at a specific airport on a given day during a certain time period. It is often used to manage air traffic at highly-crowded airports, and it also helps prevent repeated delays caused by multiple flights trying to take off or land simultaneously.
In a slot machine, symbols appear on a reel or row (depending on the game) and are arranged in combinations that earn credits depending on a pay table. Symbols vary in theme and design but typically include classics like fruits, bells, and stylized lucky sevens. A player can insert cash or, in older machines with a bill validator or credit meter, a paper ticket with a barcode into a designated slot to activate the machine and spin the reels. Modern video slot machines operate similarly to their mechanical predecessors but use a computer program instead of physical reels and handles to determine winning and losing combinations.
Slot receivers are usually a little shorter and smaller than outside wide receivers, and they must excel in running precise routes. They also need to have great blocking skills, especially when lined up close to defensive positions on run plays. They need to block (or at least chip) nickelbacks, outside linebackers, and safeties. In addition, on running plays that go to the middle of the field, they need to provide protection for the running back by picking up blitzes from secondary players.