How to distinguish the speed and instantaneous speed

How to distinguish the speed and instantaneous speed

Instantaneous velocity: vector, the velocity of an instant
Average velocity: vector, the average velocity over a period of time or over a period of displacement, equal to displacement (not distance) divided by time
Instantaneous velocity: scalar, the magnitude of instantaneous velocity
Average rate: scalar, movement distance (not displacement) divided by time
For example, in the 400 meter race, the run is a circle, the distance is 400 meters, and the displacement is 0
Suppose someone runs 100 miles
The average velocity is 0 because the displacement is 0
The average rate is 400 / 100 = 4m / s
Because the speed may change in the process of running, the instantaneous speed and instantaneous speed are changing at any time, but they are basically not zero (unless he stops to rest in the process of running)