Trojan Horses: Trojan horses are programs which pretend to do one thing, but in reality snoops out your personal data, or can end up damaging it. These types conceal their identity or true intentions and are usually quite hard to detect.
Worms: Worms are programs which are able to replicate themselves over a computer network and in turn perform malicious actions. As a result it has the ability to affect other programs on the computer.
Viruses: Viruses are programs which are able to log into the personal files on a computer it has affected and as a result, can end up removing all of them. It can have serious side effects on a computers system.
Malware: Malware can be classified as trojans with a limited payload and are often not detected by most antivirus software. They may require the use of other software designed to detect other classes of malware, including spyware.
Spyware: Spyware itself is when so called “free” software is downloaded by the user. However this spyware conceals its real intentions. Spyware collects and relays data of the computer to the manufacturer, and continues to do so even if the program is never used.
Adware: Adware is simply those annoying pop-ups which constantly advertise things. These programs secretly install themselves on your computers files and are stuck there until they are cleaned up from the computers system.