Sky ATP Realm Overview
A security realm is a group identifier for an organization used to restrict access to Web applications. You must create at least one security realm to login into Sky ATP. Once you create a realm, you can enroll SRX Series devices into the realm. You can also give more users (administrators) permission to access the realm.
If you have multiple security realms, note that each SRX Series device can only be bound to one realm, and users cannot travel between realms.