Firewall
Definition
A firewall is a security system that monitors and filters incoming and outgoing network traffic based on predefined rules. It forms a barrier between a trusted internal network and untrusted external traffic.
Firewalls come in two forms: hardware firewalls (separate equipment, such as a next-generation firewall) and software firewalls. Next-Generation Firewalls (NGFW) go beyond traditional firewalls by inspecting packet contents, recognizing applications, and integrating with threat intelligence.