Types/bool

A variable type which can have one of two values: true or false. Care must be observed with the concepts of "truthy" and "falsey": different types may behave like true in a boolean context, and nil may act like false, but they are not equal. Especially significant: "true" and "false" are truthy Types/strings, different from true and false.

Used in Boolean algebra, which is the foundation of digital logic and processing.

Wikipedia has a comprehensive article on Booleans