A firewall is a protective system that lies, in essence, between your computer
network and the Internet. When used correctly, a firewall prevents unauthorized use
and access to your network. The job of a firewall is to carefully analyse data
entering and exiting the network based on your configuration. It ignores information
that comes from an unsecured, unknown or suspicious locations. A firewall plays an
important role on any network as it provides a protective barrier against most forms
of attack coming from the outside world. Firewalls can be either hardware or
software. The ideal firewall configuration will consist of both. In addition to
limiting access to you computer and network, a firewall is also useful for allowing
remote access to a private network through secure authentication certificates and
logins.