Total Addressable Market (TAM) refers to the total revenue opportunity available for a specific product or service within a particular market. It represents the maximum potential market size that a business can target, assuming there are no limitations or constraints. TAM is calculated by estimating the total number of potential customers or users and multiplying it by the average revenue per customer. This metric helps businesses understand the overall market potential and aids in strategic decision-making, such as market entry, product development, and resource allocation.