Capacitor

Capacitors are used in circuits to store electrical charge for a short time. They can be either polarised or non-polarised, which mans either that they have to be connected the right way round (like the LED) or you can connect them anyway you like.. (like the resistor). If a capacitor is polarised it has a slightly different symbol on the circuit diagram and it is marked on the case with a plus-sign (+) or a minus sign (-)