Speed:

* Definition: How fast an object is moving.

* Measurement: Only magnitude (amount). For example, 60 miles per hour, 10 meters per second.

* Direction: Not considered.

* Example: A car traveling at 60 mph on a straight road.

Velocity:

* Definition: How fast an object is moving *and* in what direction.

* Measurement: Both magnitude and direction. For example, 60 mph east, 10 meters per second upwards.

* Direction: Essential.

* Example: A car traveling at 60 mph eastward.

Key Differences:

* Direction: Velocity includes direction, speed doesn't.

* Changing Velocity: Even if the speed is constant, if the direction changes, the velocity changes. Imagine a car going in a circle at a constant speed; its velocity is constantly changing because its direction is constantly changing.

In summary:

Think of speed as how fast you are going, and velocity as how fast you are going and where you are heading.