A small motor that moves it's output arm to a position depending on the signal sent to it with a reasonable degree of accuracy & repeatability.
The brown lead with the black croc clip goes on to GND, the yellow lead goes on to the Pin 0, 1 or 2 that is being used. The red lead goes to the battery + and the battery 0V (aka GND or minus) connecting to the micro:bit GND to provide a common ground. See circuit at bottom of page.
