Vectors are mathematical objects. They are too complicated to be described by mere numbers, but like numbers, vectors have a size. However, they also have a direction. As such, they can be used to mathematically describe certain physical items that also have a size and a direction.

Velocity is an example of such a vector quantity; it has both a size or amount (speed) and a direction. What do we mean when we say that a velocity has a direction? A velocity is always forward, back, left, right, up, down or some combination of these. This makes it a perfect candidate for a vector description.

In this article we outline the basic properties of vectors, provide several examples of physical quantities that are described by them and also demonstrate how they are used to describe the world.