The main difference between speed and velocity is that velocity includes this:

units

there is no difference

magnitude

direction

Direction

Explanation:

The question is testing on vector and scalar quantities.

What are vector quantities and scalar quantities?

Quantities with both magnitude and direction are known as vector quantities while those with only magnitude are known as scalar quantities.

What are the examples of vector and scalar Quantities?

Vector quantities examples - Velocity, force, displacement, etc Scalar quantities examples - Speed, distance, temperature, mass, etc

What would be the difference of speed and velocity then?

Speed and velocity differ in that velocity has both magnitude and direction (vector quantity) while speed has magnitude only (scalar quantity).

Further Explanation;

Velocity refers to the rate of change in displacement of a body in motion It is given by, Velocity = Displacement : time Speed on the other hand is the rate of change in distance of body. It is calculated by, Speed = Distance : time Displacement is the distance in a specified direction. Velocity and displacement are vector quantity in that they have both magnitude and direction. Speed and distance on the other hand lack direction and thus are scalar quantity since they only have magnitude.