cursor

Latin cursor (runner, messenger) came from currere (to run). In classical Rome, cursors were fast foot-messengers who ran between buildings, carrying tablets and letters in official communications. The cursor was the one who ran ahead. In the 17th century, the word was applied to the sliding part of a mathematical instrument (a slide rule) that moved to indicate position — a runner that marked a point on a scale.

When video display terminals replaced teletype machines in the 1960s and 70s, engineers needed a word for the blinking mark that showed where the next character would appear. Cursor was ideal: it ran through text, it marked position, it moved ahead of typing. The DEC VT100 terminal (1978) is considered the standard that made the cursor universal in computing. The blinking underscore became the user's location in the textual space.

The mouse cursor — the arrow or pointer that tracks mouse movement on a screen — extended the metaphor. Douglas Engelbart demonstrated the first computer mouse in 1968 at the 'Mother of All Demos' in San Francisco, moving a cursor around a screen by moving a physical device. The cursor had separated from text entry and become a general-purpose pointing tool. It ran wherever the mouse ran.

Cursor in computing has now expanded to include many shapes: the arrow pointer, the I-beam for text, the hand for links, the spinning wheel for processing, the resize arrows for window edges. Each cursor shape is a visual language that tells the user what kind of action is possible. The runners proliferated; each one runs a different route.