Speed

In physics, speed refers to the magnitude of the velocity of an object.

Speed is the total distance traveled divided by the time it takes to travel it^[1].

$Speed=\frac{d D}{d t}$

Note that speed is a scalar, therefore it has no direction, and because it is a measure of magnitude, it is never negative.

Like velocity, units for its measurement are meter/second and more commonly in informal circumstances kilometer/hour and mile/hour.

References