Firewall software is commonly installed on computers in order to monitor incoming and outgoing packet requests and to block any that may be from an untrustworthy source. Firewalls and antivirus programs are the two most basic forms of computer protection.
Instead of exposing a computer when it is connected to the Internet, a firewall acts as an intermediary. Packets of information sent to the Web are first inspected by the firewall before being allowed to pass through, while any incoming information packets are also checked before a computer receives them. If there is a request that is trying to request personal information from a computer, the firewall will block it and alert the user.