The permanent magnet has magnetism itself. As the nature of permanent magnets, the magnetism will not be eliminated by outside effect.
While, electromagnets are made of coil and core. When the core is energized, the electromagnet has magnetism and it does not have magnetism when out of energy. Another difference is that the magnetism of permanent magnets does not change, but the magnetism of the electromagnet with change according to the coil turns, current and the material of the core.