A resistor limits the amount of current that can flow from one of its leads to the other in a circuit, and their resistance is measured in Ohms (Ω). The resistors you'll be working with are all through-hole axial resistors. These resistors come in a set resistance value that's expressed in ohms.
Look closely at any resistor and you’ll notice they have a number of colorful bands. This is a color code system designed to help quickly identify the value of the resistance that the component provides.