In building construction, a firewall is a structure designed to contain building fires. As an example, an attic crawlspace that covers the entire length of the building would grant a fire to roar from one end of the building to the other. Breaking up the crawlspace with non-flammable walls helps to slow the spread of a fire.
Network firewalls have a alike function. A firewall is a network security strategy, either a program or an actual device, that breaks up a network to incorporate viruses and hackers.
Imagine two large fish tanks side by side, divided by a wall. We want to allow the blue fish to mingle, but we must keep the carnivorous fish on the left away from the baby fish on the correct. Whether or not we opened a computer-controlled door in the wall, programmed to only allow blue fish to pass but no one else, that would be a fishtank firewall.
Network firewalls 'segment" the network. Local traffic—the info that moves among the computers in that segment—doesn't go through the firewall to the more spectacular network outside. And info that doesn't must reach anybody inside the firewall is blocked out, precisely like the carnivorous fish in our example.
A Proxy is another network security tool. Proxies are replacements for Internet servers. When a computer requests a web-site from the world wide web, a main hub provides the IP address. A firewall may interfere with this, and declare that no one inside the firewall can surf the Internet. The Proxy is then the "official" way past the firewall.
A free proxy server has a list of "authorized" sites. When the user's computer requests the address from the Internet, the proxy checks it against the list, and if the website is approved, it authorizes the firewall to let the traffic through. Whether or not the web-site is not approved, then the firewall sends a message saying "you aren’t authoritative to visit this internet-site. "
