Final answer:
The ALU is the part of a processor that handles logical comparisons and calculations. It is critical for performing the necessary mathematical and logical operations that allow computers to process instructions given by software.
Step-by-step explanation:
The component of a processor that handles all logical comparisons and calculations is known as the Arithmetic Logic Unit, commonly abbreviated as the ALU. The ALU is a fundamental building block of the central processing unit (CPU) and is responsible for performing arithmetic operations, such as addition and subtraction, and logical operations, like comparing numbers to determine which is larger. It's a critical component for the functioning of any computer as it processes the instructions given to it by the software through mathematical and logical reasoning.
Other options mentioned, such as registers, buses, and the control unit have different functions within the CPU. Registers provide fast access storage for the ALU, buses are pathways that transfer data between different parts of the computer, and the control unit directs the operation of the processor and its components, but it's the ALU that actually performs the computations.