Here's a breakdown:

* Position: Where an object is located in space. This can be described with coordinates (like x, y, z) or relative to a reference point.

* Change: The difference in position over a period of time.

* Rate of change: How quickly the position is changing. This is calculated by dividing the change in position by the time it takes for that change to occur.

In simpler terms: Velocity tells you how fast an object is moving *and* in what direction.

Examples:

* A car traveling at 60 miles per hour to the east has a velocity of 60 mph east.

* A ball falling straight down has a velocity that increases as it falls.

Let me know if you'd like more details or examples!