Firewalls for business and pleasure?

Firewalls have become an expression being used more and more in the daily speech. 
 

It means two things in our world;
One is the physical firewalls (routers/broadband dividers).
The other one is software that protects your computer or your network.

These programs often have multi functions built in, like for example: built in antivirus protection. You also have functions in order to block pop ups (windows popping up). There is also often protection against spam (junk mail) or built in filter to increase the security for children, in order to prevent children from reaching unpleasant sites.

These functions have one thing in common. They block infringements from outside as worms and Trojans.