Electric field lines start on a negative charge and end on a positive charge. They form closed loops. They point in the same direction as the electric force experienced by a negative charge. Equipotential lines end on a negative charge and start on a positive charge. They form closed loops. They are parallel to electric field lines. Electric fields are stronger where neighboring field lines are further apart. Neighboring field lines cross. An electric field is produced by an electrically charged particle that is static. Equipotential lines are produced by an electrically charged particle, static or moving. A magnetic field will be produced by a stationary positive point charge. It will also be produced by a spinning neutron or a moving electron. A stationary neutron does not produce a magnetic field. We use directed lines to visualize a magnetic field pointing from the north pole of a magnet to the south pole of a magnet.