Fuzzy logic is a form of knowledge representation that allows for notions without precise definitions. It was introduced in 1965 by Lotfi Zadeh as an extension of traditional binary sets to fuzzy sets where elements can belong to multiple sets with varying degrees of membership. Fuzzy logic uses fuzzy sets that assign membership degrees between 0 and 1 rather than crisp 0 or 1 values, allowing for flexible and easy implementation of machine learning techniques to mimic human reasoning. It has been applied in various consumer products and industrial systems such as anti-lock brakes, auto transmissions, copy machines, and cruise control.