The used market is the resale channel where secondhand equipment is bought and sold. In cyber security, that can include laptops, phones, servers, routers, drives, and other hardware that may still contain data, configuration secrets, or embedded software from a previous owner. A device that looks functional can still carry risk if it has not been wiped, inspected, or verified.
This matters because attackers and defenders both use the used market. Threat actors may buy inexpensive hardware for disposable infrastructure, parts replacement, or testing, while defenders may source low-cost spares for lab work or temporary deployments. The security question is not only whether the device powers on, but whether it has trustworthy provenance, clean storage, and current firmware. Safe handling usually means secure erasure, hardware inspection, and replacement or reinstallation of untrusted components before reuse.