A mathematical technique for dealing with imprecise data and problems that have many solutions rather than one. Although it is implemented in digital computers which ultimately make only yes-no decisions, fuzzy logic works with ranges of values, solving problems in a way that more resembles human logic.
Fuzzy logic is used for solving problems with expert systems and real-time systems that must react to an imperfect environment of highly variable, volatile or unpredictable conditions. It "smoothes the edges" so to speak, circumventing abrupt changes in operation that could result from relying on traditional either-or and all-or-nothing logic.
A Matter of Degree
The concept was conceived in 1964 by Lotfi Zadeh, former chairman of the electrical engineering and computer science department at the University of California at Berkeley, while he was contemplating how to program software for handwriting recognition. Zadeh expanded on traditional set theory by making membership in a set a matter of degree rather than a yes-no situation. See set theory