Identity proofing is the enrollment stage that gathers and validates evidence about a real person. It can check document authenticity, match records, confirm possession of trusted credentials, and assess whether the presenter is connected to the claimed identity.
Proofing is different from later authentication, which checks that the same enrolled user is returning. Strong proofing can increase confidence while collecting highly sensitive information, so assurance level should match the risk and unnecessary evidence should not be retained.
ELI5
Identity proofing is the first check used to connect an account with a real person. It examines evidence to decide whether the person creating the account owns the identity they claim.
For example, a service can check whether an identity document is genuine and belongs to the person presenting it. Later sign-ins may use a password or passkey instead of repeating the complete proofing process.
