The primary function of a CPU (Central Processing Unit) in a computer system is to execute instructions and perform calculations necessary for the proper functioning of the computer. It acts as the "brain" of the system, processing data and managing the flow of information between various hardware components. The CPU is responsible for fetching instructions from memory, decoding them, executing the necessary operations, and storing the results.

The interaction between the CPU and other hardware components is facilitated through a system known as the von Neumann architecture. In this architecture:

Memory (RAM): The CPU interacts with the computer's memory to fetch and store data. Instructions and data are temporarily stored in RAM (Random Access Memory) for quick access by the CPU.

Input/Output (I/O) Devices: The CPU communicates with peripherals and external devices, such as keyboards, mice, and storage devices, to send and receive data. The CPU manages the flow of information between these devices and the computer's memory.

Cache Memory: Modern CPUs often have cache memory, a small, high-speed memory storing frequently accessed instructions and data. This helps improve the overall speed and efficiency of the CPU by reducing the need to fetch data from slower main memory.

Bus System: The CPU communicates with other components through a system of buses (data bus, address bus, and control bus). The data bus transfers actual data, the address bus specifies the location in memory, and the control bus manages the coordination of activities.

Motherboard and System Clock: The motherboard provides the physical connections between the CPU and other components, and the system clock synchronizes the operations of the CPU and other hardware components.