--- title: Authentication description: To access Couchbase Server, users must be authenticated. Authentication is a process for identifying who is attempting to access a system. pubDate: 2026-08-17T09:53:44.266Z antora: editUrl: https://github.com/couchbase/docs-server/edit/release/8.0/modules/learn/pages/security/authentication.adoc xref: xref:server:learn:security/authentication.adoc[] --- [Consult the llms.txt file for a full list of contents](/llms.txt) [View original HTML](/server/current/learn/security/authentication.html) # Authentication To access Couchbase Server, users must be authenticated. _Authentication_ is a process for identifying who is attempting to access a system. Subsequent to successful authentication, _authorization_ can be performed, whereby the user's appropriate access-level is determined. Authentication can be performed by means of a _username_ and _password_, assigned to each administrator or application. Authentication can also be performed by means of _X.509 Certificates_: these support _Transport Layer Security_, by establishing the identity of a client or server through _digital signatures_. They also provide keys to support _on-the-wire_ encryption, according to the conventions of _Public Key Infrastructure_ (PKI). Couchbase Server assigns each user to one of two _authentication domains_: the _local_ domain consisting of users whose credentials are maintained by Couchbase Server itself; the _external_ domain consisting of users whose credentials are maintained remotely — for example, on an _LDAP_ server or a _SAML IdP_. For detailed information on these topics, see: * [Understanding Authentication](authentication-overview.md), which provides an overview of all the key aspects of Couchbase authentication. * [Usernames and Passwords](usernames-and-passwords.md), which lists the conventions whereby usernames and passwords can be designed and passed by administrators and applications. * [Authentication Domains](authentication-domains.md), which contains full explanations of the _local_ and _external_ authentication domains supported by Couchbase Server. * [Certificates](certificates.md), which provides a detailed overview of how certificates are supported by Couchbase Server, for the authentication of clusters, nodes, and client applications.