Capacitors are electrical components that can store electrical energy for a period of time. It is said in a given time period because although the capacitor is charged with a certain amount of electrical charge, the charge will be discharged after a while, depending on the capacity of the capacitor. The capacity of the capacitor is measured in Farad units. In practice this size is too large, so use smaller units such as microfarad (μF), nanofarad or picofarad.
Capacitors have two types:
a. Polar Capacitors
In the polar capacitor, the determination of the poles of the capacitor when it is to be connected to a circuit, and only works on the DC voltage. Polar capacitors have a relatively large capacity
b. Non polar capacitors
The non-polar capacitors do not have poles so they can be mounted in reverse position in the circuit, and can be connected to AC voltage. The size of non polar capacitors is relatively small, with nanofarad and picofarad units