Pot: from cookware to control
In the kitchen, a pot holds liquid. On the bench, it controls current with a twist of the shaft.
To most people, a pot is a round metal vessel used for cooking or storage. It sits on a stove, holds soup or beans, and is made of steel, aluminum, or copper. The word comes from Old English and has meant essentially the same thing for over a thousand years.
On the shop floor, a pot is an electromechanical variable resistor, often called a potentiometer. It consists of a resistive element, usually a coil of wire or a carbon film, connected to a wiper that moves along it. When you turn the shaft or move the slider, the wiper contacts different points on the resistor, changing the resistance in the circuit. In audio equipment, a pot is mounted behind the volume knob; turning the knob rotates the shaft, which moves the wiper, which adjusts the resistance and thus the voltage supplied to the amplifier. In test equipment and industrial controls, pots set calibration, trim bias voltage, or dial in a setpoint.
The metaphor is sound. The earliest electromechanical resistors were wound coils, physically bulky and visually similar to metal pots when packed into cabinets. The name stuck. By the early twentieth century, "pot" was standard shop terminology in radio and electrical work.
Modern pots are shrunk to thumbnail size and mounted on circuit boards as trim pots or panel pots, often with a screwdriver slot instead of a shaft for manual adjustment. Their function has not changed: they remain simple, passive devices with no moving parts except the wiper, and no need for a power supply to operate. This simplicity and reliability made them, and keeps them, a fixture in every technician's toolkit.
The dictionary entry
pot
(noun, shop talk and trade slang)
A simple electromechanical device used to control resistance or voltage (often to adjust sound volume) in an electronic device by rotating or sliding when manipulated by a human thumb, screwdriver, etc.