A firewall that is provided by software. It often refers to a personal firewall in a user's computer, but software firewalls may be installed in servers as well. Contrast with hardware firewall. See ...

Software installed in a user's computer that offers protection against unwanted intrusion and attacks coming from the Internet. Personal firewalls are available from numerous security vendors, and ...

Learn how firewalls have progressed from simple packet filtering to more sophisticated application-level filtering. Webopedia.com defines a firewall as “a system designed to prevent unauthorized ...