Q.What is a CPU? Name and briefly explain its three main components.

The CPU is the processing centre of the computer; the answer should define it and then name its three internal parts with a one-line role for each.

Together these three parts let the CPU repeat its fetch-decode-execute-store machine cycle millions of times a second.

Meaning. The central processing unit (CPU), as Section b explains, is the part of the computer that carries out processing — it interprets and executes instructions and controls the working of all the other units. It is called the brain of the computer and, in a modern machine, is a single chip called a microprocessor.

Its three main components:

1. Arithmetic and Logic Unit (ALU). This part performs the actual computations — arithmetic operations (addition, subtraction, multiplication, division) and logical operations (comparisons such as equal to, greater than, less than, and true/false decisions). All the real work of producing a result happens here.
2. Control Unit (CU). This part manages and coordinates the whole system. It fetches instructions from memory, decodes (interprets) each one, and sends the necessary control signals to the ALU, memory, and input/output units so the instruction is carried out. It does not itself calculate; it directs.
3. Registers. These are very small, very fast storage locations inside the CPU that temporarily hold the data and instructions the CPU is working on at that instant. Being inside the CPU, they are the fastest storage in the computer, though they hold only a tiny amount. Using these three parts, the CPU repeats a fetch–decode–execute–store machine cycle over and over, millions of times a second.
   ✓Final answer

   The CPU is the brain of the computer that executes instructions and controls all units. Its three components are: (i) the ALU, which performs arithmetic and logical operations; (ii) the control unit, which fetches, decodes, and directs the execution of instructions; and (iii) registers, the fast temporary storage inside the CPU.

Do not stop at naming the three parts — a short answer must give a one-line role for each. Also avoid mixing up the ALU (which calculates) and the control unit (which only directs); this is the most common confusion.