What is CPU? Discuss any three important functions performed by CPU.

CPU (Central Processing Unit): CPU is the abbreviation for Central Processing Unit, more commonly called processor. It is the brain of the computer where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system. A CPU has four primary functions: Fetch: The CPU retrieves the instruction that it needs to run from program memory. Decode: Here, the compiler breaks down the program into Assembly Language, which the CPU understands. An assembler then translates Assembly Language into binary code, which the CPU can manipulate to execute the given instructions. Execute: Based on the instructions, the CPU can perform one of three actions: Using its Arithmetic Logic Unit (ALU), it can calculate complex mathematical functions. Move data from one memory location to another. Jump to different addresses in the program based on decisions made by the CPU itself. Write back: Typically, each action taken by the CPU produces some output. The CPU takes this output and writes it into the computer's memory. For example, if a program adds two operands (e.g., 3 and 5), the output (8) would be written back into a specific address.