A substitute good is a product or service that can be used in place of another, providing a similar function or fulfilling a similar need. It is a viable alternative to the original good, offering consumers a choice between two or more options. Substitute goods are often seen as interchangeable, with one being able to replace the other without a significant difference in quality or satisfaction. This can be due to similarities in price, features, or overall utility. For example, coffee and tea can be considered substitute goods as they both provide a source of caffeine and can be used to satisfy a similar craving. However, it is important to note that substitute goods are not always identical and may have slight differences that can influence consumer preferences. In economics, the concept of substitute goods is used to understand consumer behavior and market dynamics, as the availability of substitutes can impact demand and pricing for a particular good.