Glossary
WebAuthn
The W3C Web Authentication API that lets websites register and authenticate users with public-key credentials held by an authenticator.
WebAuthn (Web Authentication) is the browser half of FIDO2. A website calls navigator.credentials.create() to register a credential and navigator.credentials.get() to authenticate. The browser adds the real origin of the page, forwards the request to a platform or roaming authenticator, and returns a signed response the server verifies with the stored public key.
Key concepts include the relying party ID (usually the site's domain), user presence and user verification flags, discoverable credentials (passkeys) and optional attestation, which tells the server which authenticator model created the credential.