![Scott uses a mouse](https://cdn.statically.io/img/static.wikia.nocookie.net/memoryalpha/images/6/62/Scott_uses_a_mouse.jpg/revision/latest/scale-to-width-down/180?cb=20070914125438&path-prefix=en)
"Hello, computer."
A computer mouse was a manual input device on computers of the 20th and 21st centuries. The device was known as a mouse because a cord, which connected the device to the computer, resembled the tail of a mouse. A person provided input to a computer via the mouse by rolling the mouse on a flat surface and clicking buttons.
Montgomery Scott mistook the device for an audio-input device when he traveled back in time to 1986, speaking into it when his attempts to talk directly to the computer were unsuccessful. (Star Trek IV: The Voyage Home)
Kathryn Janeway used the device to access Chronowerx Industries database in 1996. (VOY: "Future's End")