Modular hardware is equipment built from separate, replaceable parts rather than one sealed unit. Common modules include power boards, storage, sensors, network cards, and interface boards. Each part can often be tested, repaired, or swapped without discarding the entire device.
In cyber security, modular design matters because it can reduce downtime, improve forensic inspection, and limit the impact of a failure or compromise. A damaged or suspicious module can be isolated and examined, while trusted parts remain in service. It also helps defenders restore systems after tampering or hardware faults. At the same time, modular systems can expose more internal connectors and buses, which attackers may target to intercept data, alter firmware, or replace a component with a malicious one. Good security practice is to inventory modules, verify authenticity, and control replacements carefully.