Every person living on earth is a consumer. Some items or services you have to buy before its consumption or utilization wherein other items you consume without buying directly. And in some cases you either consume or utilize before you pay. In its vast meaning, word 'consumer' holds rich and strange meaning depends on its arena.
In legal point of view, the definition of 'consumer' shall be: "an entity (a person or an organizational institution) that buys any material things or hires any services for valuable consideration is a consumer". This definition includes deferred payment system too. The term consumer does not include an entity who obtains goods or services for resale or for any commercial purpose. However, persons who avail goods or services exclusively for the purpose of earning their livelihood by means of self employment are considered as consumers.