The main components of the CPU are– control unit (CU), arithmetic nd logical unit (ALU) and a set of registers.

1. Control Unit :
   1. Responsible for controlling the movement of data and instructions in and out of the memory and the CPU.
   2. Decodes the fetched instruction and initiates the desired operation to be performed by the ALU.
2. Arithmetic and logical unit (ALU) :
   1. Receives signal from CU and accordingly performs the desired operations on data.
3. Registers :
   1. Size of CPU depends on the power of CPU.
   2. Are of two types : General purpose and Special purpose registers (Program counter, Instruction register, Memory address register (MAR), Memory data register (MDR), Accumulator (ACC)).

CPU also contains a clock to accurately control the speed and operations of the computer in general, and of the CPU in particular.