An Arithmetic Logic Unit (ALU) is a fundamental component of a computer's central processing unit (CPU). It performs basic arithmetic operations, such as addition and subtraction, as well as logical operations like comparisons. The ALU takes input data, processes it according to specified instructions, and produces output results. The ALU works in conjunction with other components of the CPU, such as the control unit and registers. It is essential for executing instructions in computer programs, enabling tasks ranging from simple calculations to complex data processing. Overall, the ALU plays a crucial role in the functionality of modern computing systems.