diff --git a/index.rst b/index.rst
index af2e5ce..9051005 100644
--- a/index.rst
+++ b/index.rst
@@ -35,6 +35,7 @@ Agate is the `OBiBa `_'s central authentication server which
web-user-guide/groups
web-user-guide/applications
web-user-guide/tickets
+ web-user-guide/realms
web-user-guide/administration
.. toctree::
diff --git a/web-user-guide/realms.rst b/web-user-guide/realms.rst
index 19d83de..66f39c6 100644
--- a/web-user-guide/realms.rst
+++ b/web-user-guide/realms.rst
@@ -1,2 +1,38 @@
Realms Management
=================
+
+A Realm is a data access object that provides authentication capabilites for Agate users user the underlying datasource's specific API to discover authorization data.
+
+Realm Types
+-----------
+
+LDAP Realm
+~~~~~~~~~~
+
+A realm that authenticates users by using Lightweight Directory Access Protocol to query a Directory Access Agent.
+This realm uses a user's Distinguished Name (DN) template to build queries.
+
+Active Directory Realm
+~~~~~~~~~~~~~~~~~~~~~~
+
+The only difference between this and the LDAP realm is the query template.
+This realm queries by using a combination of a search filter and search base.
+
+SQL Database Realm
+~~~~~~~~~~~~~~~~~~
+
+``mysql``, ``mariadb`` and ``postgresql`` are supported.
+This realm queries the user's password with the salt style used by the database.
+
+Salt styles include:
+
+- ``NO_SALT``: used when the password is in plain text.
+- ``CRYPT``: uses the database's underlying cryptographic method to decrypt the password.
+- ``COLUMN``: the salt column must be the second column included in the query.
+- ``EXTERNAL``: uses the specified algorithm to decrypt the password.
+
+
+Open ID Connect Realm
+~~~~~~~~~~~~~~~~~~~~~
+
+A realm that uses the OpenID Connect (`OIDC `_) protocol to authenticate users.