Resistance

Resistance is how much the flow of current is reduced or impeded. All circuits have some resistance from the wire and components that make up the circuit; however, most circuits include resistors that add extra resistance to the circuit. These resistors enable us to limit the flow of charged particles within the circuit. Resistance is measured in Ohms.

Using the water in a pipe analogy again, resistance is the smallest part of the pipe that is impeding the water flow.

Now let's see how these three properties work together by examining Ohm's law.