Bidding is an offer (often competitive) to set a price tag by an individual or business for a product or service or a demand that something be done. Bidding is used to determine the cost or value of something.

Bidding can be performed by a person under influence of a product or service based on the context of the situation. In the context of auctions, stock exchange, or real estate, the price offer a business or individual is willing to pay is called a bid. In the context of corporate or government procurement initiatives, in Business and Law school students actively bid for high demand elective courses that have a maximum seat capacity though a course bidding process using pre allocated bidding points or e-bidding currency on course bidding systems. The price offer a business or individual is willing to sell is also called a bid. The term "bidding" is also used when placing a bet in card games. Bidding is used by various economic niches for determining the demand and hence the value of the article or property, in today's world of advanced technology, the Internet is a favoured platform for providing bidding facilities; it is a natural way of determining the price of a commodity in a free market economy.

Many similar terms that may or may not use the similar concept have been evolved in the recent past in connection to bidding, such as reverse auction, social bidding, or many other game-class ideas that promote themselves as bidding. Bidding is also sometimes used as ethical gambling in which the prize money is not determined solely by luck but also by the total demand that the prize has attracted towards itself.