A bidder's proposal is a formal document that outlines the terms and conditions of a business transaction. It is typically used in competitive bidding situations, where multiple parties are vying for the same contract or project. The term 'OFFER' is used to describe the bidder's proposal, which is usually submitted in writing and includes details such as the price, timeline, and any other relevant information. The OFFER is then evaluated by the potential customer, who will decide which bid to accept.