Computer architecture basics: Which component is commonly called the “brain” of a computer system because it fetches, decodes, and executes instructions?

Introduction / Context:
The phrase “brain of the computer” is a popular way to describe the part of a system that coordinates and performs instruction execution. Knowing the precise component associated with this role is fundamental to computer organization.

Given Data / Assumptions:

• The component oversees fetch–decode–execute.
• It integrates arithmetic/logic and control sequencing.

Concept / Approach:

The Central Processing Unit (CPU) encompasses the control unit and the Arithmetic Logic Unit (ALU), and often register files and caches. It orchestrates instruction flow, performs operations, and interfaces with memory and I/O.

Step-by-Step Solution:

Verification / Alternative check:

Any CPU block diagram shows the control unit directing the ALU and registers while communicating over buses—hence the metaphor “brain.”

Why Other Options Are Wrong:

• ALU: performs arithmetic/logic only.
• Control unit: sequences operations but lacks the complete processing role alone.
• Memory: stores instructions/data; does not process them.
• None: incorrect because CPU is correct.

Common Pitfalls:

• Assuming ALU equals CPU; the CPU comprises multiple cooperating units.

Final Answer:

CPU.