EMI is the nomenclature of "electromagnetic interference". EMI filters prevent electromagnetic interference between electronic devices. They range from small resistances up cards with an electronic design and several integrated capacitors, depending on the type of apparatus where needed.

One hertz is one cycle per second, meaning repeating cycle as an event. For example, hertz is applied physics measuring the number of times for a second wave (either acoustic or electromagnetic) is repeated or can be applied, among other uses, to ocean waves that reach the Beach vibrations per second or a solid. The quantity that measures the frequency hertz is called,in this regard, the inverse of the period. One hertz is an oscillation frequency of suffering a particle over a period of one second.