Most incandescent lamps have a rated life of 1000 hours and halogen lamps 2000 hours. Some special purpose lamps will have shorter life's as low as 25 hours and some as long as 8000 hours.
Standard products not special products i.e. those with lives rated at between 1000-4000 hours will be replaced FOC if they fail within 2 months of the date of purchase. The rated lives are only an average so it is quite normal for some to fail early in the same way that some will go on working for years.
Warranties and guarantees.
Led products have a very long life in much the same way as a television, but in the same way as a television by default they are only guaranteed for 12 months from the date of purchase. Some manufacturers will offer a warrantee for a longer period, these warrantees are usually subject to conditions, such as domestic use only or based upon an average daily usage or even in some cases will not be covered if the temperature of the fixture operates outside the operating temperature of the lamp. It is impossible for the end user to know in advance if their fixture is going to comply but you need to take it as a bonus if you lamps are covered.
Most other lamps will have a 12 months warranty but it does depend upon the rated life of the product.