Many measurable physical phenomena are described in terms of scalar quantities, which have only a magnitude. On the other hand, magnetic fields are directional. In a magnet, the magnetic field vector always points from the north pole to the south pole. In the space around the magnet, the vectors vary in both direction and magnitude. This is the behavior you see when you dump iron filings around a bar magnet, for example.
Some materials have a feature known as ferromagnetism .
An atom consists of a number of negatively charged electrons, orbiting around a positively charged nucleus. These electrons also possess a quantity known as spin , which is roughly analogous to a spinning top. The combination of orbital and spin motions is called the angular momentum of the electron. The planets also have an angular momentum as they revolve about the sun. Now, the angular momentum of an electron is a vector quantity, meaning it has direction.