A Vector is something that has two and only two defining characteristics.
- Magnitude: the meaning of magnitude is 'size' or 'quantity'
- Direction: the meaning of direction is quite self-explanatory. It simply means that the vector is directed from one place to another.
The significance of 'direction' can be seen in the difference between velocity and speed. In physics, speed is a pure scalar, or something with a magnitude but no direction --such as 5 m/s. 5 meters per second does not tell us which way the object is moving. It gives us no clue about the direction. All that we know from the speed is the magnitude of the movement. On the other hand, velocity, in Physics, must be expressed as a vector with both a magnitude and a direction. For instance, 5 m/s Eastward is a velocity because it tells you the magnitude of the movement, 5 meters per second, as well as the direction which is Eastward.
To illustrate the idea of magnitude, look at the two red circles below. Circle A has greater magnitude than circle B.
The direction of the vector is North East or diagonally up and right (Short of measuring the angle with a protractor, we cannot be more exact with this picture)
In terms of direction, there is no difference whatsoever between 55°north of west, and 35° west of north.