A device key is a value used by some applications or services in activation, registration or device verification. Its exact meaning is implementation-specific rather than a universal television standard. It may need to remain private alongside the associated identifier, especially when the combination permits account changes or access to a device-linked management interface.
A practical example
A player can display both an identifier and a key for its own registration process. A user should follow that publisher's verified workflow rather than entering the pair into an unrelated website found by searching a similar app name.
A common misunderstanding
Treat a device key as potentially sensitive until its role is clear. Do not post it publicly or assume a support request requires sending it to an unverified person.
Related terms
Stable technical definition. Editorial approach