How important is control unit in a computer system ?

The control unit is highly important in a computer system as it directs and coordinates all operations of the CPU. When a program reaches into memory, the control unit (CU) of CPU reads the program instructions one by one and executes the program as follows:

1. The Control Unit determines the type of instruction i.e., whether it is an arithmetic (calculations) or logical (comparisons) or I/O (reading or writing) type of instruction.
2. For arithmetic or logical type of instructions, Control Unit directs the ALU (Arithmetic and logic unit) to carry out the instructions.
3. For Input type of instruction, Control Unit directs the Input unit to carry out the instruction and for Output type of instruction, it directs the output unit to carry out the instruction.

Thus, without the Control Unit, the CPU would not function effectively, impacting the overall performance and functionality of the computer.