Batteries supply electric energy which powers the ignition system, the starter motor, and the lights of the vehicle. If you need to jump-start your vehicle in the morning, your battery is failing. When a battery starts deteriorating, it's time to being the vehicle in to have the battery tested to determine weather it needs to be replaced or not.
A starter is a motor (electric, hydraulic or pneumatic) that rotates the internal combustion engine to initiate the engine's operation. It is an important part of your car's engine and their failure would translate to your car's failure. When your car's starter develops problems, seek expert help.