What is a “Firewall”?

A firewall is An electronic boundary (or physical piece of hardware) that prevents unauthorized users and/or packets of data or information (e.g., files and programs) from accessing a protected system.

Firewalls filter incoming and outgoing traffic that goes through your computer system. A typical firewall uses sets of rules to inspect the network packets as they come in or go out of your network connections. These rules are set to either allow the traffic through or block it. The rules of a firewall can inspect predefined characteristics of the packets, including (but not limited to):

  • The protocol type.
  • The source or destination host address.
  • The source or destination port.

Firewalls can greatly improve the security of a host or your computer network. They can be used to do one or more of the following things:

  • To protect and insulate the applications, services and computers on your internal computer network from unwanted traffic coming in from the public Internet.
  • In reverse, to limit or disable access from local hosts of the internal network to the services of the public Internet.
  • To support network address translation (NAT). NAT allows your internal network to use private Internet Protocol (IP) addresses and share a single connection to the public Internet. It is typically done either with a shared pool of automatically assigned public addresses, or a single dedicated IP address.

What does a Firewall mean to you?

Your computer network may be protected by a firewall – either at work or at home. If not, and you store, transmit or use sensitive data please, consider getting one.