What is does means Warranty?

Returns and refunds, warranties and complaints.

What is a warranty?
Warranties are similar to guarantees, in that they provide a legally-binding assurance that any problems caused by manufacturing defects during a set period will be remedied.
However, unlike guarantees, the customer normally pays for this extra protection. For example, electrical retailers often offer to sell a warranty on their products which covers accidental damage, the cost of repairs and replacement parts.
Warranties - also known as "extended warranties" - have a similar effect to insurance policies - indeed some are issued and underwritten by insurance companies. They are sold on the basis that they will provide the customer with "peace of mind" over the first few years of ownership.
Remember that as a supplier, any warranty you offer is in addition to your statutory responsibilities under the Sale of Goods Act. A supplier cannot, for instance, refuse to deal with a customer's complaint about a faulty product simply on the grounds that the warranty on the product has expired.
In law, a supplier is still liable for any breach of contract - for example, if the goods are not fit for their purpose, or of satisfactory quality - for a period of up to six years (five years from the date the problem arises, in Scotland).

Source info from : www.businesslink.gov.uk