Firewalls can help protect computers by blocking potentially hostile connection attempts.
Your Internet-connected computer is probed many times daily by automated attack tools seeking ways to break into and take over your system. Severe attacks may delete important data, crash your system, spawn new attacks, or even steal personal information, such as passwords and credit card numbers. A firewall can help protect your computer by blocking potentially hostile connection attempts.
Unit firewalls (firewalls that are designed to help protect multiple computers in a university department, or a home or apartment complex network) and properly configured personal firewalls (firewalls that you can install on your own computer) can each provide effective security to suit various needs. For home use, personal firewalls are often free.