A dedicated device that stores private keys in isolation and signs transactions internally, so the key never reaches an internet-connected computer.
Why it matters
A hardware wallet protects the key. It does not judge whether a transaction is a good idea — it displays the request and asks. In the Ledger Connect Kit compromise and the Radiant Capital breach, devices behaved exactly as designed while funds were lost.
What you can check
A hardware wallet makes a narrow promise: the key does not leave the device, and the device shows you what you are about to authorise. It does not promise that the software you use to reach it is intact, or that the entropy used to generate the key was sound. Those are separate claims, each verifiable separately.
Where it showed up
Records in the Incident Tracker that turn on this: Ledger Connect Kit supply chain attack.
Not advice. Definitions are for understanding, not instruction. Nothing here is financial, legal, tax or security advice.