PEMF's (pulsed electromagnetic fields)
In general pulsed electromagnetic fields are magnetic fields with the following properties: frequency, flux density (intensity, or amplitude), and wave form. Static magnets possess only one of these properties, flux density.
Electrical currents are a flow of electrons. Every electric current produces a corresponding magnetic field around it´s space. In addition, every magnetic field induces electricity (Ampere´s law and Maxwell equations).
A pulsed (pulsating) electromagnetic field (PEMF) can be produced and controlled by "chopping" the electrical current up into numerous pulse-packets, or bundles. Contrasted with a static magnetic field, a PEMF can be generated with specifically-intended content (frequency), field strength (intensity, flux density or amplitude) and flow characteristics (wave from).
Learn more about the history and effects of PEMF's here.