Speed is just a magnitude. It is a scalar quantity. To see the difference, you could have a velocity, and this isn't maybe particular to this problem because they don't give us the units, but you could have a velocity of negative 5 meters per second. Maybe if we're talking about on the x-axis, this would mean we're moving leftward at 5 meters per second on the x-axis. The magnitude is 5 meters per second. This is the magnitude. The direction is specified by the negative number.