Hardware lifecycle is the full path a device or component follows from deployment and active use through maintenance, repair, reuse, resale, and final retirement or disposal. Different parts age at different rates, so a laptop may be retired while its display, battery, or storage still has value. That is why reused parts can be practical, but they also need to be handled as assets with history, not as anonymous scrap.
In cyber security, lifecycle management matters because old hardware can expose data, trust, or access. Discarded drives may still hold files, firmware settings may reveal network details, and reused components can enter new systems without proper inspection. Defenders reduce risk by tracking inventory, wiping or destroying sensitive storage, updating firmware, verifying refurbished parts, and separating reuse from formal disposal. Attackers, by contrast, may target poorly retired equipment to recover information or abuse weakly vetted hardware in a supply chain.