A firewall is a software program or a piece of hardware that helps to protect a computer or a network from hackers, viruses, and worms that try to infiltrate the system through the internet.
These can be preinstalled on a computer, which most do come with a built in firewall such as windows defender. If your firewall does not recognize a program that you are trying to run on your computer or a program that is trying to access your computer through the internet it will block that program or application from running or from accessing the computer essentially putting up a wall in front of the program and not allow it to access the internet or vice versa and access the computer.
There can be different firewalls on different devices on your network. For example, most routers have their own built in firewalls that help give your network a little added protection.
Modems have firewalls as well. So you can have a set up that has no less than 3 firewalls before you can access the internet or before a hacker, virus, or worm can get into your computer. It would have to go from the internet, past the modem firewall, past the router firewall, and then past your computer’s firewall.
You can also purchase added security for your computer. The most notable security system for computers is Norton antivirus software. This is one of the best if not the best security software available to the average computer owner. It of course comes with firewall protection.