COMING through an internet connection to a network or computer system. Ifincoming information does not pass the rules stored in the firewall, it is not allowed through.Not only does a firewall block unwanted traffic, but it can also help block malicious software from infecting your computer.Firewalls represent the first line of defense in home network security.A firewall acts as a gatekeeper. It monitors attempts to gain access to your operating system and BLOCKS unwanted traffic or unrecognized sources.A firewall acts as a BARRIER or filter between your computer and another network such as the internet. You could think of a firewall as a traffic controller. It helps to protect your network and information by managing your network traffic, blocking unsolicited INCOMING network traffic, and validating access by assessing network traffic for ANYTHING malicious like hackers and malware.Hence, it is clear from the above points that a Firewall means a software program or a piece of hardware between computer and internet connection.