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. That is the direction. Your velocity could be negative 5 meters per second, but your speed would just be 5 meters per second. Your speed is 5 meters per second whether you're going to the left or to the right.