What's the difference between velocity and speed?

Velocity and speed and vector and scalar quanities respectively. Vector quantities have both direction and magnitude (size), whilst scalars only have magnitiude. It is important to distinguish between the two because velocity refers to both how fast something is going and in which direction while speed only tells you how fast something is going. An example of a velocity would be 2m/s north. You can see that this gives us more information than just saying that an object is travelling at 2m/s. Velocity allows for another form of comparison between two travelling objects as it will tell you their direction in relation to each other.