July 13, 2020
A capacitor is a pair of metal plates that is used to store an electric charge. The metal plates are separated by an oxide (= non conductive material) and are usually rolled together in a cylinder to gain space. It acts similarly to a battery, can be charged and discharged. But unlike batteries which use a chemical reaction to store electrical energy, the capacitor directly uses the electrons and keeps them on one of the metal plates while the other one is depleted (electrons are removed).
Here is its schematic symbol
One of its advantages is that it can be charged and discharged very fast; as compared for example to a battery. Capacitors are heavily used in electronics boards when filtering electronic signals for example.