what is "sale"?

sale is the exchange of a product or service for money. a car is sold to someone in exchange for money. goods are products which people either need or want, for example, cars can  be classified as goods. service, on the other hand, are activities which a person or group performs for another person or organization. for instance, an auto mechanic performs a service when he repairs a car. a doctor also performs a service by taking care of people when they are sick.