What is a CPU?

A CPU is the electronic circuitry that performs basic arithmetic, logic, controlling, and input/output operations as specified by a computer program.

Microprocessor chips can contain multiple CPUs called multi-core processors, allowing them to handle several tasks simultaneously, unlike single-core processors. CPUs can also be multi-threaded, enabling a single CPU to handle multiple threads of execution at once.

Key components of a CPU include the Arithmetic Logic Unit (ALU) for arithmetic and logic operations, the Address Generation Unit (AGU) for calculating memory addresses, the Memory Management Unit (MMU) for translating logical addresses and providing memory protection, and the cache for reducing data access time from main memory.

CPUs follow a three-step process: fetch, decode, and execute. It fetches instructions from memory, decodes them into signals, and then sends those signals to the appropriate components.