The Central Processing Unit (CPU) is often referred to as the “brain” of the computer. It is responsible for executing instructions and carrying out all the essential calculations and tasks that enable the computer to perform operations. The CPU controls the flow of information between the different parts of the computer and ensures that tasks are carried out in a timely and efficient manner.

Key Components of the CPU:

• Arithmetic and Logic Unit (ALU): This unit performs all the arithmetic (e.g., addition, subtraction) and logical (e.g., comparisons such as greater than, less than, equal to) operations needed by the system.
• Control Unit (CU): The CU is responsible for coordinating and directing the operations of the CPU. It fetches instructions from memory, decodes them, and directs the ALU and other parts of the computer to execute them.
• Registers: These are small, high-speed storage locations within the CPU. They temporarily store data, instructions, and addresses that are frequently used during computation. Key registers include the Program Counter (PC), Instruction Register (IR), and Accumulator (AC).
• Cache: A small but very fast memory located inside or close to the CPU. It stores frequently accessed data and instructions, reducing the time the CPU spends fetching data from slower main memory (RAM).

How the CPU Works:

The CPU follows a series of steps to execute instructions, known as the Fetch-Decode-Execute cycle:

1. Fetch: The control unit fetches the instruction from memory (RAM).
2. Decode: The instruction is decoded to determine what operation needs to be performed.
3. Execute: The ALU executes the operation and stores the result in a register or memory.
4. Repeat: The process continues until the program has completed execution.