diff --git a/FAQ.md b/FAQ.md
index 9097da2..c56022a 100644
--- a/FAQ.md
+++ b/FAQ.md
@@ -1618,3 +1618,8 @@ For normal non-admin user, the device list on web console only shows devices ass
 
 <img width="402" height="210" alt="image" src="https://github.com/user-attachments/assets/80f7a8eb-2160-4a52-983b-30a7deb43303" />
 
+# Device group vs address book
+
+The device groups are actually security groups, to restrict access to certain machines from internal team.
+
+Address books are used to organize devices and manage passwords.
\ No newline at end of file