Fuzzy logic is a mathematical system for dealing with uncertainty and vagueness, based on the theory of fuzzy sets by Lotfi Zadeh.
Unlike classical logic with binary truth values, fuzzy logic allows continuous values in the interval [0,1], which represent the membership of an element to a set.
Fuzzy logic is formally defined by fuzzy operators (e.g., t-norms and t-conorms) and fuzzy rules that model complex decision processes.
It finds wide application in control engineering, pattern recognition, and artificial intelligence, especially where fuzzy or imprecise data are present.
Definition:
Fuzzy logic is a logic system based on fuzzy sets that uses fuzzy truth values between 0 and 1 to model uncertainty and vagueness in information processing.
Source:
Zadeh, L. A. (1965). "Fuzzy sets." Information and Control, 8(3), 338-353.