For people who took auto shop in high school, replacing the distributor cap and rotor was one of the first mechanical repairs they'll remember.
A running engine sends a large amount of electricity through the ignition coils to the rotor, which turns inside the distributor.
When your distributor cap or rotor goes bad you could be left stranded and unable to start your vehicle.
Are the brakes on your car squealing, is the car pulling to one side, or is there a giant puddle on the garage floor? All of these problems point to an issue with your braking system.