Magnet
A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to a magnetic field, by one of several other types of magnetism.
Electropermanent magnet
An electropermanent magnet is a special configuration of magnetic materials where the external magnetic field can be turned on and off by applying a current pulse. The EPM is based on a common magnetic configuration called magnetic latch (right picture). A general example of this configuration assembly is built by a permanent magnet block with two plates of soft magnetic materials (generally iron alloys) on each side of the block. Those two plates exceed the dimensions of the permanent magnet. Because the plates had a higher permeability than the air, they will concentrate the magnetic flux of the permanent magnet. When a third (external) soft magnet plate is placed touching the other two plates, the magnetic flux will flow confined in the soft magnetic plates creating a closed magnetic circuit and the magnetic field produced by the magnet will be maximum (approximately the magnet remanence).
An EPM has at least two permanent magnets in between the plates. The magnetic field generated by the EPM is produced by the permanent magnets not by electric currents and this is the main difference with the electromagnets. An EPM uses only a pulse of current to magnetize one of the magnet in a desired direction (turning on and off the external magnetic field of the latch). After changing the direction of the magnet no current is needed and the field will return to depends on the permanent magnets.