This document provides definitions and concepts related to revenue. It defines revenue according to international and US accounting standards. Revenue is the inflow of economic benefits during a period from delivering goods or services. Three criteria must be met for revenue recognition: measurability, existence of a transaction, and substantial completion of the earning process. Revenue is generally recognized at the point of sale. Exceptions include revenue recognized over production or receipt of cash. Services revenue is recognized as work is completed. Interest, royalties and dividends can be recognized as they are earned or received. Developments in revenue standards emphasize recognition when revenue arises rather than realization. Fair value measurement is also increasingly important.