A slot is a narrow notch, groove, or opening. The term has a variety of uses, ranging from an assignment to an opening in a job. The chief copy editor, for instance, has occupied a slot in a job for 20 years. Another common example is the slot designated for air-traffic authority aircraft.
A slot receiver typically lines up slightly behind the line of scrimmage and has a more flexible and agile route-running style than an outside receiver. A slot receiver’s speed and agility are critical to his success. He also must be able to block well on running plays. A slot receiver needs excellent hands and quick feet.
Another common use for slots is as receivers for signals. Since these are normal member functions, they follow C++’s rules when called directly. They can also be invoked using the signal-slot connection. When a signal is emitted from an object, it can trigger the execution of the receiver in the context thread. Otherwise, it will report a runtime error.
The technology used to run these machines has evolved a lot over the years. Mechanical slot machines have been replaced by computer-controlled models, but the core game is the same: the player pulls a handle to rotate a series of reels. The reels have pictures printed on them. A pay line, or ‘pay line’, is usually marked in the middle of the viewing window. Symbols on the reel can be single or multiple, depending on how they line up with the pay line.