Which component is primarily responsible for executing instructions within a computer?

The component primarily responsible for executing instructions within a computer is the central processing unit (CPU). The CPU acts as the brain of the computer, processing data and executing commands given by software applications. It performs arithmetic and logical operations, manages data flow between different components of the system, and coordinates the actions of other hardware devices.

When a program is run, the CPU fetches instructions from memory, decodes them, and then executes them in a cyclical process. This makes the CPU integral to the overall functionality of a computer system as it drives the execution of tasks and operations that users and applications rely upon.

In contrast, input devices facilitate user interaction with the computer, memory modules serve as temporary storage for data being worked on, and storage devices provide long-term data retention. Each of these components plays a vital role in a computer's operation, but they do not execute instructions as the CPU does.