Firewalls: Keeping Things Contained
Firewalls Explained
In the real world a firewall is a fireproof (or fire-resistant) wall designed to prevent the spread of fire through a building.
In the electronic world a firewall is any of a number of security schemes that prevent unauthorized users from gaining access to a computer network or that monitor transfers of information to and from the network. (source: Dictionary.com)
The only way to make your comupter 100% secure against electronic attack is to unplug it from the Internet. Obviously, this is not practical, so security features have been developed to thwart malicious behavior over a computer network. The firewall is just one of a number of defenses, but it is a very important one.
Think of the Internet as a series of hallways. Firewalls are the security doors which some people (i.e. data) may not pass through, while others can.
Firewalls are a mainstay of Information Assurance, protecting systems from malicious attacks of all sorts. Every network of any size should be protected by a firewall system. There are a variety of different types of firewall and dozens of different programs and vendors, so finding a firewall that fits your needs should be simple.
