Computer Hardware and Software

CSS Computer Science (Optional) — Paper-I, Section-A, Topic I, p.6-9. Covers: Computer Hardware and Software, Explanation, Comparison Chart.

Definitions

Hardware: any physical device used in or with a computer — something that can be physically touched (e.g., hard drive, monitor, printer, keyboard, mouse). Hardware provides the physical means for computation but does nothing on its own.
Software: a general term for a collection of computer programs, procedures, and documentation that perform a task on a computer system — an ordered sequence of instructions for changing the hardware's state. Software cannot be physically touched; it is stored on hardware and executed by it.

Interdependency: neither hardware nor software is useful alone. Hardware without software has no instructions to follow; software without hardware has nothing to run on. Software tells hardware which tasks to perform, and hardware carries them out.
Worked example: a monitor and mouse are hardware; the browser running on the machine is software. A video game uses hardware (CPU, RAM, hard drive, video card) but is itself software. An operating system (Windows/macOS) is software that provides the interface through which a person controls the hardware and other software.
Hardware is manufactured once and physically installed; software can be copied, updated, and reinstalled indefinitely without any physical loss.

Aspect	Hardware	Software
Nature	Physical, tangible	Logical, intangible
Examples	CPU, RAM, keyboard, printer	OS, MS Word, a compiled game
Durability	Wears out physically over time	Does not physically wear out; can degrade via corruption/bugs
Failure mode	Mechanical/electrical failure	Bugs, crashes, corruption
Reproducibility	Cannot be copied — must be manufactured	Can be copied/reinstalled without loss
Dependency	Needs software to be useful	Needs hardware to run
Development	Designed via engineering/manufacturing processes	Developed via programming/software engineering processes

Hardware and software are mutually dependent, not independent — a common wrong-answer trap frames one as "more important."
Software does not physically wear out, but it can still "fail" via bugs or corruption — don't equate "non-physical" with "never fails."

Define hardware and software with one example each.
Give a worked example showing hardware and software working together in a single device.
Why can software be reinstalled without loss, while hardware cannot?