The function of a firewall is to manage all outgoing and incoming traffic that goes out and comes in to your system. Nevertheless this elucidation paints an extremely primal image about firewalls. When we talk about PC and traffic, we talk about the switching over of data packets. Data packets are made use of by computers within a network to swap over info. This is the way we interchange info within a LAN or by means of the web. This is furthermore a means by which damaging computer viruses go into the system. What the firewall does is that it checks which packets are permitted to enter the system and which packets are permitted to exit the computer. Why is it necessary for the firewall to perform these tests? All this has got to do with the security of the PC. The past has proven to us that there is nothing such as a faultless system. The most complicated computer systems also have hot faults. With the purpose of preventing these faults from coming into your machine, you ought to make use of a brute force method to data packet management. Your computer ought to just communicate with the computer that you would like it to. A firewall will just permit exchange of information with the computers you decide on. It is somewhat like a telephone, which will just let you to converse with a few predefined phone numbers. Firewalls can surely be configured, and you can alter the setting if you want nevertheless that is a different account. The primeval Greeks had an aphorism: "You cannot bolt your cupboard and also fling the key in it simultaneously." Not anything is completely protected; no matter what you do, safety can and will at all times be breached if you do not take proper measures. This is the reason why firewall exists. They are similar to sentries who look after your gate, following your particular orders.