Which component is responsible for executing instructions in a computer?

The processor, also known as the Central Processing Unit (CPU), is the main component responsible for executing instructions in a computer. It performs calculations, runs programs, and carries out the commands of both software and hardware. The processor interprets and processes instructions fetched from memory, utilizing its various components such as the arithmetic logic unit (ALU) and control unit to manage operations.

In contrast, RAM (Random Access Memory) temporarily stores data and instructions that are actively in use but does not execute them. Input devices, like keyboards and mice, facilitate user interaction with the computer but are not involved in instruction execution. Backing storage refers to devices such as hard drives and SSDs, which store data permanently, but again, they do not execute instructions; rather, they provide data to the processor when needed. Thus, the processor is the key component that performs the actual execution of instructions in a computer system.