A Next-Generation Firewall (NGFW) is a type of firewall that can filter traffic on all OSI layers, as well as provide advanced security features such as application awareness, intrusion prevention, and threat intelligence. A NGFW can replace a traditional router at the edge of a network and provide better protection against network attacks.
A proxy is a server that acts as an intermediary between clients and servers, forwarding requests and responses. A proxy can filter traffic on the application layer (layer 7), but not on the lower layers of the OSI model.
A layer 3 switch is a device that can perform both switching and routing functions. A layer 3 switch can filter traffic on the network layer (layer 3), but not on the higher or lower layers of the OSI model.
A load balancer is a device that distributes incoming traffic among a group of servers, improving performance and reliability. A load balancer can filter traffic on the transport layer (layer 4), but not on the higher or lower layers of the OSI model.
References
What is a Next-Generation Firewall?
What is a Reverse Proxy vs. Load Balancer?
Load Balancers Vs Api Gateway Vs Reverse Proxy
Reverse Proxy and Load Balancer: Understanding the Difference
CompTIA Network+ Certification All-in-One Exam Guide, Eighth Edition (Exam N10-008)
