The XOR operator (exclusive OR) is a logical operator used in programming and digital circuits. It outputs true only when the inputs differ; that is, one input is true and the other is false. For example, if you have two boolean values, A and B, the result of A XOR B is true if either A is true or B is true, but not both. In binary terms, the XOR operator can be represented as follows: 0 XOR 0 = 0, 0 XOR 1 = 1, 1 XOR 0 = 1, and 1 XOR 1 = 0. This property makes the XOR operator useful in various applications, including error detection and cryptography, where it helps to create secure data transmissions.