How is a magnetic force in an electromagnet created?

An electromagnet uses electricity to create the magnetic field. Moving charges create magnetic fields. Knowing that, if we have a lot of copper wire (with a suitable insulator) wrapped around an iron core, we can send direct current through that wire, and it will create a magnetic field. The magnetic field will magnetize the iron core, and the core becomes a magnet. Wrapping wire around a nail and connecting a battery to the ends of the wire will make a simple electromagnet.