In the human body, electricity works like this: the membrane potential of our cells, when at rest, is ever so slightly negatively charged. Positively charged elements—sodium, magnesium, potassium, and calcium ions—are afloat in the plasma between those cells. These are your electrolytes. When touched, the cells open channels in their membranes and allow these ions to pass through them. Think of the sluice gates in canals that let water in and out.
