Which part of a computer system is hardware?

A compiler is a software program that translates code written in a programming language into machine language that a computer can understand. It is not a physical component, but rather a tool used by developers to create software applications, thus classifying it as software rather than hardware.

The kernel is a core component of an operating system that manages system resources and allows communication between hardware and software. As an integral part of the software ecosystem, the kernel operates in memory but is not itself a physical part of the computer, and therefore is not considered hardware.

An operating system is a software layer that manages hardware resources and provides services for computer programs. It includes user interfaces, system utilities, and file management, but it is not a physical part of the computer system, categorizing it firmly as software rather than hardware.