It’s common knowledge that bad things exist on the internet. To prevent others from maliciously getting to data on your computer, it is important to take the precautionary measure of installing anti-virus software, a firewall, or both. So what’s the difference between the two and what does each of them do?

A firewall is a “filtering” device. This filtering can be either built in or user defined. It controls incoming traffic usually by “rules” created by you or the firewall administrator to prevent invasive probing and attacks to the servers, PCs and other devices on your local or wide area network. It can also control or regulate the outward bound traffic from your internal network to sites outside and prevent access to sites not considered appropriate by the network management decision makers. It also has the ability to trap and record attempts which may violate the rules set up on the particular firewall and provide reporting for these types of infractions.

Anti-virus software works by using “definitions”. These are images of viruses that are used during a scan to find an infection. As an anti-virus program scans your machine it searches every file and checks the file against the definitions. If there is a match, in other words it finds a file containing a virus with a exact match to the definition, then it will appear as a virus on the scanner and inform you in the report at the end. The anti-virus will then either delete the file (recommended) or “quarantine” it, meaning it will be stored in a folder totally isolated from the rest of the computer. People use this function if they need to send the virus to an antivirus company (like Mcafee or Avg), so they can investigate. Usually, deleting the virus is still the best course of action. Some anti-virus programs will delete the infection during the scan, and some will wait until the end of the scan before offering you to delete them.

All anti-virus programs update automatically, so that they always have the latest definitions. You should never turn off the auto update function in the anti-virus as this would put your machine at risk. The virus definitions are constantly being updated.

Many users worry about antivirus protection, but “spyware” and “malware”, which can track what you do and even what you type, can be just as dangerous. Most antivirus programs include the mechanisms needed to remove these threats as well.

So basically, a firewall stops bad things from getting onto your computer, or you going to a dangerous site. An anti-virus program deletes anything that gets through, using current known definitions of threats that are out there, and keeps your computer free of threats.