**The purpose of the ALU is to perform mathematical operations such as addition, subtraction, multiplication and division.** Additionally, the ALU processes basic logical operations like AND/OR calculations. Also known as the arithmetic logic unit, it serves as the computational hub of the Central Processing Unit (CPU) for a computer system.

An ALU can be programmed to perform any series of complicated arithmetic or logical calculations. It is the computational capacity of the ALU that determines the power of a computer system’s CPU. In more complex systems, the ALU is divided into two units: the arithmetic unit (AU) and the logic unit (LU).