• Arithmetic Logic Unit stands for Arithmetic Logic Unit. It is a critical component of the CPU. It does all basic arithmetic and logical operations (addition, subtraction, multiplication, and division). The ALU is usually constructed with direct access to the random access memory as input and output.
• The acronym CU stands for Control Unit. It's one among the CPU's most important components. The CU's primary function is to advise on the most effective technique of working. It directs all associated processes to the processor's specific elements. 
• A digital circuit that performs arithmetic and logic operations is known as an arithmetic logic unit (ALU). It is the most essential component of a computer's central processing unit (CPU). ALUs on modern CPUs are extremely powerful and sophisticated. Modern CPUs have a control unit in addition to ALUs (CU).
• One or more ALUs load data from input registers to accomplish the majority of a CPU's operations. A register is a little piece of storage that comes with a CPU. The ALU is told what operation to do on the data by the control unit, and the result is stored in an output register by the ALU. The data is moved between these registers, the ALU, and m by the control unit.

Read More: Explain what do you understand by registers? Also explain the various types of registers.