What is a firewall and how it helps?

Hi all,
Firewall is a network security system that is used to protect computer networks from unauthorized access. It prevents malicious access from outside to the computer network. A firewall can also be built to grant limited access to the outside users.



The firewall consists of a hardware device, software program or a combined configuration of both. All the messages that route through the Firewall are examined by specific security criteria and the messages which meet the criteria are successfully traversed through the network or else those messages are blocked.

Can you please mention some benefits of the firewalls?:confused::confused: