A Firewall is a network security device that monitors all incoming and outgoing traffic and permits, blocks, or drops data packets based on a defined set of security rules. In other words, a firewall establishes a barrier between your internal network and the incoming traffic from untrusted external sources such as the internet to block malicious traffics such as viruses and hacking.
A firewall can be implemented in the form of either a software or hardware device though it is best to have both. A software firewall is a program installed on your computer to regulate traffic through applications or port numbers. In contrast, a hardware firewall is a physical device installed between your network and gateway.
