Software firewalls are installed on your computer like windows firewall, ZoneAlarm Free Firewall, Tinywall, Anti NetCut3, Comodo Free Firewall PeerBlock.
you can modify it; permitting you some control over its function and safety features. A software firewall will save your computer from outside access to your computer, and, depending on your choice of software firewall, it could also provide the guard against the most common Trojan programs or e-mail worms. Many software firewalls have user-defined controls for setting up safe file and printer sharing and to block insecure applications from running on your system. Additionally, software firewalls may also include privacy controls, web filtering and more. The disadvantage to software firewalls is that they will only defend the computer they are installed on, not a network so each computer will require to have a software firewall installed on it.
Software firewalls run on a computer that can also do other functions. Most personal firewalls that guard a single computer fall into this category. After all, the purpose you get a personal firewall is to protect your computer while you are using the Internet not to make your computer a dedicated firewall. Some enterprise firewalls are also software-based