Why is a control unit referred to as the central controller of a computer?

Q. Why is a control unit referred to as the central controller of a computer?

Answer :-

In simple words:-
CU acts as a supervisor by controlling and guiding the operation taking place

Explanation:-
The CU controls and guides the interpretation, flow and manipulation of all data and information. The CU sends control signals until the required operations are done properly by ALU and memory. Another important function of CU is the program execution i.e., carrying out all the instructions stored in the program. The CU gets program instructions from memory and executes them one after the other. After getting the instructions from memory in CU, the instruction is decoded and interpreted i.e., which operation is to be performed. Then the asked operation is carried out. After the work of this instruction is completed, control unit sends signal to memory to send the next instruction in sequence to CU.

The control unit even controls the flow of data from input devices to memory and from memory to output devices.