I never really understood what a firewall was or how it worked until taking IS101. I always just thought of it as some nerdy IT lingo. Then I learned that there are two types of firewalls and what they do. I learned that a host firewall comes installed on your device to protect it from malicious attacks from the internet bad guys. I liken this to the deadbolt and peephole of your front door. This is installed on your house as a protective measure to vet and keep the bad guys out. I then learned that the other type of firewall is called a network firewall. This type of firewall is configured by your internet service provider (ISP). I like to think of this type of firewall as TSA at the airport or Boarder Patrol at the boarders of the country. Vetting and providing security for those who want to enter to ensure they have good intentions and are safe to do so.
So in short, a network firewall is the first line of defense when you are connected to the internet (TSA and Boarder Patrol). The second line of defense is your host firewall (deadbolt and peephole). Hopefully my explanation and understanding of these firewalls helps others to better understand how these types of firewalls work.
