A firewall is a network security system uses protocols to takeover outgoing and incoming network connections/ traffic of a computer. In other words, it acts as a barrier between networks to monitor incoming and outgoing network data and decides whether to allow or block; means that the ruled traffic only allowed via a network connection which is pre-mentioned in its policy and the rest of others are denied.
A firewall is a network security system uses protocols to takeover outgoing and incoming network connections/ traffic of a computer. In other words, it acts as a barrier between networks to monitor incoming and outgoing network data and decides whether to allow or block; means that the ruled traffic only allowed via a network connection which is pre-mentioned in its policy and the rest of others are denied.