Logical operators are also called Boolean operators after George Boole, an English mathematician and logician. The results of Boolean operations are either **TRUE** or **FALSE**.

Boolean operators are used to establish a relationship between two operands.

Key logical operators used in JavaScript are: AND – OR – NOT

Example: Assume that the variable **Number1 = 9** and that **Number2 = 4**

Operator | Description | Expresssion | Output |
---|---|---|---|

&& | AND | (Number1 < 10 && Number2 > 1) | TRUE |

|| | OR | (Number1 == 5 || Number2 == 5) | FALSE |

! | NOT | !(Number1 == Number2) | TRUE |

All logical and arithmetic operations are carried out by a computers ALU, which is short for **A**rithmetic and **L**ogic **U**nit. The ALU is a vital part of the computer’s CPU (Central Processing Unit). All computer systems work using the binary number system and in order to carry out their operations they make use of logic gates. The CPU contains many logic gates that are set up to allow complex binary manipulations.

Name | Logic Gate |

AND | |

OR | |

NOT |