A firewall is a network security system that monitors and controls incoming and
outgoing network traffic based on predetermined security rules. A firewall typically establishes a
barrier between a trusted network and an untrusted network, such as the Internet.
Firewalls filter the network traffic within a private network. It analyses
which traffic should be allowed or restricted based on a set of rules. Think of the firewall like a
gatekeeper at your computer’s entry point which only allows trusted sources, or IP addresses, to
enter your network.
There are Five types of firewall given bellow:
● packet filtering firewall
● circuit-level gateway
● application-level gateway (aka proxy firewall)
● stateful inspection firewall
● next-generation firewall (NGFW)