[DOCS] Adds descriptions and examples to spaces security doc (#30113)

docs/spaces/securing-spaces.asciidoc

@@ -2,6 +2,73 @@
 [[spaces-securing]]
 === Securing spaces
 
-With security enabled, you can control who has access to specific spaces. You can manage access in **Management > Roles**.
 
-image::spaces/images/securing-spaces.png["Securing spaces"]
+With a Gold or Platinum license, you can control which roles have access to 
+each space. To get started, navigate to **Management > Roles**.
+
+[role="screenshot"]
+image::images/spaces_secure_all_privileges.png[]
+
+==== Setting privileges
+
+Access for all spaces in {kib} is governed by a concept called "minimum privilege."
+There are three options for minimum privilege:
+
+
+[cols="2*^<"]
+|===
+
+|`all`
+|Users have read/write access to all spaces in {kib}. Additionally, 
+users can create, edit, and delete individual spaces. This extends to spaces 
+that users create in the future.
+
+|`read`
+|Users have read-only access to all spaces in {kib}. This extends to spaces 
+that users create in the future.
+
+|`none`
+|Users do not have the all-spaces access.  You must set access on 
+individual spaces.
+
+
+|===
+
+Once you set the minimum privilege for all spaces, you can then add read and write 
+access to individual spaces. 
+
+
+==== Examples
+[cols="2*^<"]
+|===
+
+s|To provide
+s|Do this
+
+|Full access to all spaces
+|Set the minimum privilege to `all`.  This grants 
+full access to all spaces. In this case, you can't
+customize access to specific spaces.
+
+|Read-only access to all spaces, with full access to specific spaces
+|Set the minimum privilege to `read`,
+then grant the `all` privilege to individual spaces as needed. You can't revoke 
+access to an individual space.
+
+|Read-only access to a specific space
+|Set the minimum privilege to `none` to prevent all-space access,
+then set the `read` privilege for an individual space, 
+as shown below.
+
+|===
+
+[role="screenshot"]
+image::images/spaces_secure_specific_spaces.png[]
+
+
+
+[float]
+=== Viewing all space privileges
+
+To see which roles have access to each space, click *View summary of spaces privileges*.
+