A contract by which a seller transfers or agrees to transfer the ownership of goods to a buyer in exchange for a money price. If ownership is to pass at a future time the contract is called an agreement to sell. The contract, which need not be in writing, may contain express terms. Terms may also be implied by law (see also implied condition); for example, that the seller has a right to sell, that the goods correspond with the description under which they are sold, and that the goods are of satisfactory quality and are reasonably fit for the buyer's purpose. Unless the parties agree otherwise the seller must hand over the goods in exchange for the price and the buyer must pay the price in exchange for the goods. Much of the law governing the sale of goods is codified in the Sale of Goods Act 1979, as amended by the Sale and Supply of Goods to Consumers Regulations 2002.
http://www.berr.gov.uk/whatwedo/consumers/fact-sheets/page38311.html Quick Facts on the Sale of Goods Act from the Department of Business website