https://www.youtube.com/watch?v=1z11-DAm9x4
A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents And magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to the magnetic field.

The spinning of the electrons around the nucleus of an atom creates a tiny magnetic field. The electrons in most objects spin in random directions, and their magnetic forces cancel each other out.

This is a good simple example of a magnetic field.....