firewall
network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules
packet filter
software which inspects packets transferred between computers and blocks or allows them
Screened-subnet firewall
type of network firewall
virtual firewall
network firewall service or appliance running entirely within a virtualized environment
Great Firewall
censorship of the Internet in the People's Republic of China
Little Snitch
application firewall for macOS
Ingress filtering
computer network packet filtering technique
Uncomplicated Firewall
simplified netfilter interface
application firewall
a form of firewall that controls input/output or system calls of an application or service
personal firewall
firewall usually designed to protect a single personal computer