A worm is like a virus—it also replicates itself. However, it can stand on its own and does not need another program to run. It usually infects your computer’s networking features, which includes its internet connection.

Spyware and adware go hand-in-hand. Spyware is a kind of program which gathers information, specifically browsing habits.

It tracks down what kind of sites you visit, and adware will generate ads that fit with your interest which spyware based on information it gathered in first place.

Malware is malicious software. It’s any program that is useless, or worse, destructive. A Trojan a program pretending to be good but once it’s deep in your system it proves to be quite opposite.

In spite of all their differences, they have one thing in common: they are out to give you headaches by rendering your computer unusable.

To protect your computer as much as possible from being infected, here are four dangerous activities that you should avoid, or at least minimize:

• Opening email attachments

Do not open any email attachments if they aren’t scanned by antivirus software. Worms can spread through email, so even a friend can unwittingly send you one by way of an attachment.

• Internet File-sharing

In file-sharing via internet, your computer is exposed and open to others it is communicating with. If other computers’ files can be transferred to yours, same thing can be said about a virus, if others are infected.

• Downloading free software of questionable origins.