A Boolean data type is a data type that can be either one of these two values: true or false. The boolean data type was originally added to the C++ language by the ISO/ANSI(International Standards Organization/American National Standards Organization) committee in 1998. Type bool expressions are named after the English mathematician George Boole, who formulated rules for mathematical logic. Boolean expressions also end up with a value of either true or false. Boolean expressions are used in branching and looping statements. In programming, a boolean can be used with conditional statements (statements that only happen when the right condition is met).