IT Security
...uter. A firewall program acts as a layer between the computer and the internet and it enables the user to specify which 'ports' in his operating system external programs can access and even to control which programs on his own computer are allowed to access the internet. This has the advantage that even if a piece of trojan software has unwittingly been downloaded and installed, it won't be allowed to send private information over the internet because the computer owner will not have granted it access. Viruses are harder to protect against. Anti-virus software that scans incoming email messages is a good start but it is only really useful if it is kept up to date. In addition, many viruses come from people we alread...