The instrument in your car that shows you how far you've driven is called an odometer. When you buy a used car, it's important to check the odometer to see how many miles it has traveled.
The odometers in today's cars are electronic, but there may be an odometer on any form of transportation, including your bike, and some of these may run mechanically. There's historical evidence that odometers were used in both ancient Greece and ancient China. In the seventeenth century, odometers measured the distance traveled by horse-drawn carriages. Odometer comes from the Greek roots hodos, "way," and metron, "a measure."