A network firewall is a security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules. It acts as a barrier between a trusted internal network and an untrusted external network, such as the internet. An example of a network firewall is a firewall appliance, such as Cisco’s ASA or Palo Alto’s PA series.
A host-based firewall is a security system that is installed on individual hosts or computers. It monitors and controls incoming and outgoing network traffic based on predetermined security rules. This type of firewall is typically used to protect individual systems from malicious network traffic, such as viruses and worms. An example of a host-based firewall is Windows Firewall, which is included with the Windows operating system.