Wikipedia

• Fuzzy logic is a form of many-valued logic in which the truth value of variables may be any real number between 0 and 1.
• Fuzzy set are sets whose elements have degrees of membership.
• Fuzzy control system is a control system based on fuzzy logic—a mathematical system that analyzes analog input values in terms of logical variables that take on continuous values between 0 and 1, in contrast to classical or digital logic, which operates on discrete values of either 1 or 0 (true or false, respectively).