To describe the<em> change in position</em> you need to indicate the distance between the final and initial positions and the direction in which you moved. The distance is the magnitude.
The quantities that need both magnitude and direction to be described are named <em>vector quantities</em> or, just, vectors.
<em>The vector quantity that defines both the distance and direction between two positions </em>describes the <em>change in your position</em> and is named displacement. For instance, to indicate how you can goe to the supermarket from your house you cannot just say walk 2 miles. You need to indicate the direction; let's say 2 miles North. In this case, the displacement when you goe from your house to the supermarket is 2 miles North. And it is different of the displacement when you comeback from the supermarket to your house, because it would be 2 miles South.
