Resistance is how much the circuit resists the flow of the charge. This makes sure the charge does not flow too fast and damage the components. In a circuit, a light bulb can be a resistor. If electrons flow through the light bulb, then the light bulb will light up. If the resistance is high, then the lamp will be dimmer. The unit of resistance is “Ω”,  which is called omega, and pronounced “ohm”, it is the name of the inventor of Ohm’s law.