In terms of Oracle Identity Manager = Identity certification is the process of reviewing user entitlements and access-privileges within an enterprise to ensure that users have not acquired entitlements that they are not authorized to have. It also involves either approving (certifying) or rejecting (revoking) each access-privilege.
Certifications can be scheduled to run on a regular basis to meet compliance requirements. Managers use the identity certification feature to review their employees’ entitlements to access applications and data. Based on changes reported by the identity certification module, managers can authorize or revoke employee access as needed.
You can create four types of certifications. Each type of certification addresses a particular use-case—a specific type of review that enterprises commonly perform. Each type of reviewer reviews a different subset of access-related data from a specific point of view