can someone please help with an explaination of electrical and magnetic fields... I want to understand how inductance works but im having troubles because i cant quite grasp what a field is. The assertion that electrical fields have no mass is a tad confusing, If energy is propagated by a field surely the field must have mass of some sort: Its my understanding that electrons can not flow between insulated conductors and i currently perceive fields to be almost like sound waves, in the sense that an excited electron produces a "wave" that may propagate through a medium of some sort, the wave may then have an effect on another electrically insulated electron. This doesnt figure because as far as i know fields dont behave like waves and they can travel through vacuums, in which case some sort of mass must be involved in the transfer of the electrical and magnetic energy contained in the field, something must be lost by inductance even if it's not electrons! Also with shielding; something tangible must be reflected by the shield. and just when i thought it was starting to make some sense! side-thought: Do 0Ω superconductors also generate electromagnetic fields in the presence of a current?