New cars bought from the manufacturer typically come with a three year warranty, or a warranty that covers you up to a certain mileage (often 60,000). During this time, you're protected against most faults that aren't considered "wear and tear", such as those related to the engine, transmission, gearbox, suspension, steering or cooling system.
Only certain warranties will include cover for wear and tear, and even still, you might be required to pay towards parts and labour costs.
When your car's three years old or has travelled the specified distance, you'll have the option to extend your warranty for an additional price. You'll need to decide quickly, as the new cover must carry on from the manufacturer's warranty uninterrupted.
Remember, buying a used car doesn't always exclude you from a manufacturer's warranty. If the car's three years old or less, or its mileage is under the distance specified by the manufacturer, then the warranty will still apply when the car changes hands.