Another tool that you could use, especially if you access the Internet using broadband, is a firewall. Firewalls can be software or hardware, single packages or complete computers.
A firewall in a building is designed to stop the spread of fire; an Internet firewall prevents the spread of harmful files.
A firewall is a filter that has been trained to look for malicious acts that may endanger users' computers. As with antivirus software it needs to be updated regularly.
In its simplest form, a firewall looks at incoming or outgoing data – its origin, its destination and what type it is – and then makes the decision to allow it in, or out, or block it.
Some people consider 'firewall' to be the last word in Internet security, but although they are a useful tool in conjunction with antivirus software they are only part of the picture.
A detailed examination of firewalls is beyond the scope of this course. However, you should be aware that setting up firewalls can be quite time-consuming, and they may require constant tuning to remain effective. If you are not careful when setting up your firewall you may block some applications that you do want to have access to the Internet as well as the ones you don't, and you need to configure the firewall to let them through.