A categorization of the states that a key can assume during its lifetime. See [NIST SP 800-57 Part 1].
Sources:
NIST SP 800-152
The states through which a key transitions between its generation and its destruction. See Pre-activation state, Active state, Suspended state, Deactivated state, Compromised state, and Destroyed state.
Sources:
NIST SP 800-57 Part 1 Rev. 5