The starter motor is the heart of your vehicle supplying the physical force to turn the engine over and get you moving. Without the starter motor, the car will not start.
In most instances, starter motors will not fail outright but trigger a range of sypmptons as warning all is not well. Engine failing to turn, Dash light warnings, erractic performance of the electrical components or grinding sounds all point to starter motor failure.
Of course the problem may not actually be the starter motor. The problem may lie with the battery not being charged properly, alternator failure or a corroded distributor cap. .
If you have checked all these potential factors and your engine is still fialing to turn then it is most likely the starter motor will need replacing.