Explanation
AppFW and APPID are two application security features that can be used to block malicious applications regardless of the port number being used. AppFW provides policy-based enforcement and control on traffic based on application signatures. By using AppFW, you can block any application traffic not sanctioned by the enterprise. APPID identifies applications based on their behavior and characteristics, regardless of port, protocol, or encryption method. By using APPID, you can classify applications and apply appropriate security policies to them123 References:
AppSecure: Application Visibility and Control Solution Brief
Application Firewall | Junos OS | Juniper Networks
Security Policy Applications and Application Sets | Junos OS | Juniper Networks

In active/passive mode, only one node is actively processing traffic while the other node is on standby. If the active node fails, the standby node takes over.
In active/active mode, both nodes actively process traffic, distributing the load between them.
This can provide better scalability and redundancy.
In control plane clustering, one node is designated as the primary, actively handling control plane tasks such as routing protocols and management services, while the other node serves as a backup. If the primary node fails, the backup node takes over control plane duties.

Adaptive Threat Profiling (ATP) is a Juniper Networks solution that enables organizations to detect malicious activity on their networks and process it through IPS and Juniper ATP Cloud for malware and virus protection. ATP is powered by Juniper's advanced Machine Learning and Artificial Intelligence (AI) capabilities, allowing it to detect and block malicious activity in real-time.
ATP is integrated with Juniper's Unified Threat Management (UTM) and Encrypted Traffic Insights (ETI) solutions, providing an end-to-end network protection solution.