A device identifier is a value a system uses to distinguish a device or installation for its own purposes. It can be created by hardware, software or an account service, depending on the implementation. Different apps on one television may therefore show different identifiers, and an identifier is not automatically a subscription or secret password.
A practical example
A player may display an installation identifier when the user registers it with that publisher. A separate streaming service can maintain another account reference, so support needs to know which system produced the identifier before using it to examine a problem.
A common misunderstanding
Do not assume every identifier is permanent across reinstalls, resets or interface changes. Preserve relevant records privately and follow the specific service's supported device-transfer or registration process.
Related terms
Stable technical definition. Editorial approach