A Firewall is a basic security device that filters traffic and is a barrier between a network and the outside world or between a system and other systems.
It refers to a network security system that plays a very important role in controlling and monitoring incoming and outgoing network traffic which is based on certain security rules that are pre-determined.
As far as the barrier is concerned, it does establish a wall between a trusted network and an untrusted network, such as the Internet.
Some of the most popular firewalls that ensure optimum security while a user is on network line are PeerBlock, Tinywall, Comodo Free Firewall.
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