Three valid source or destination conditions available as Security policy qualifiers are User, Application, and Zone. These qualifiers allow you to define the match criteria for a Security policy rule based on the identity of the user, the application used, and the zone where the traffic originates or terminates. You can use these qualifiers to enforce granular security policies that control access to network resources and prevent threats1. Some of the characteristics of these qualifiers are:

User: The User qualifier allows you to specify the source or destination user or user group for a Security policy rule. The firewall can identify users based on various methods, such as User-ID, Captive Portal, or GlobalProtect. You can use the User qualifier to apply different security policies for different users or user groups, such as allowing access to certain applications or resources based on user roles or privileges2.

Application: The Application qualifier allows you to specify the application or application group for a Security policy rule. The firewall can identify applications based on App-ID, which is a technology that classifies applications based on multiple attributes, such as signatures, protocol decoders, heuristics, and SSL decryption. You can use the Application qualifier to allow or deny access to specific applications or application groups, such as enabling web browsing but blocking social networking or file sharing3.

Zone: The Zone qualifier allows you to specify the source or destination zone for a Security policy rule. A zone is a logical grouping of one or more interfaces that have similar functions or security requirements. The firewall can apply security policies based on the zones where the traffic originates or terminates, such as intrazone, interzone, or universal. You can use the Zone qualifier to segment your network and isolate traffic based on different trust levels or network functions4.

References: Security Policy, Zones, User-ID, App-ID, Certifications - Palo Alto Networks, [Palo Alto Networks Certified Network Security Administrator (PAN-OS 10.0)] or [Palo Alto Networks Certified Network Security Administrator (PAN-OS 10.0)].