OR

Also known as the disjunction operation; output is true (1) if any input is true. Algebraic operators are '+', '|', ''

AND and OR are called binary operations because they are defined on two operands X and Y. Not is called a unary operation because it is defined on a single operand X. All of these operations are closed. That means if one applies the operation to two elements in a set Z {0, 1}, the result will be always an element in the set B and not something else.