Substitutability refers to the degree to which one good or service can be used in place of another without affecting the overall satisfaction of the consumer. Some synonyms for this concept include interchangeability, replaceability, and compatibility. Interchangeability emphasizes the ability of one item to function as a direct substitute for another, while replaceability suggests that one item can be used to replace another that has become obsolete or unavailable. Finally, compatibility implies that two items are similar and can be used together without causing negative effects. All of these terms are important in economics and business, as they help to quantify the degree to which goods or services can be substituted for each other.