A firewall is a network security tool that inspects and filters traffic between devices in a private computer network and the internet. Firewalls allow or deny incoming and outgoing network traffic based on defined rules. This enables users to block unauthorized data as well as prevent malware and other security threats from breaching the network.

Firewalls generally come as hardware network devices or software applications. Hardware firewalls are placed in a central network location to filter traffic for an entire network. Software firewalls are installed on endpoints to filter traffic to and from specific devices.
There are also different types of firewalls, including packet filtering firewalls, stateful inspection firewalls, proxy firewalls, network address translation (NAT) firewalls, and next generation firewalls (NGFW)

A firewall is a network security tool that inspects and filters traffic between devices in a private computer network and the internet. Firewalls allow or deny incoming and outgoing network traffic based on defined rules. This enables users to block unauthorized data as well as prevent malware and other security threats from breaching the network.

Firewalls generally come as hardware network devices or software applications. Hardware firewalls are placed in a central network location to filter traffic for an entire network. Software firewalls are installed on endpoints to filter traffic to and from specific devices.
There are also different types of firewalls, including packet filtering firewalls, stateful inspection firewalls, proxy firewalls, network address translation (NAT) firewalls, and next generation firewalls (NGFW)