The term that describes how fast something is going is speed.

Here's why:

* Speed is a measure of how quickly an object changes its position over a certain amount of time. It tells us how fast something is moving without considering its direction.

* Velocity, on the other hand, is a measure of how fast something is moving and in what direction.

So, if you want to know how fast a car is going, you're talking about its speed. If you want to know how fast it's going and in what direction, you're talking about its velocity.