Here is a small keyterms guide to aid you in the various terminology dealing viruses and other harmful programs on the Internet.
A virus is a malicious program that reproduces itself and is capable of causing harm to files or other programs on a computer. Most viruses require human assistance to spread from computer to computer. A virus is loaded onto your computer by a hacker without your knowledge and runs against your wishes turning your computer into a zombie.
A worm is a malicious program that replicates itself until it fills all of the storage space on a drive or network. A worm is considered to be a sub-class of viruses and unlike a virus, a worm does not require the assistance of humans to travel from computer to computer. One example of a worm would be for a it to send out a copy of itself to everyone in your e-mail address book and then replicate itself again to send itself out to everyone listed in each of the receiver's address book and so on and so on creating a chain effect.
A Trojan Horse is a malicious security-breaking program that appears to be a benign and legitimate program, but it is designed to have destructive effects on a computer and may open a backdoor. Unlike a virus, a Trojan Horse does not replicate itself. One example is a free game that someone could download, but it actually is a Trojan horse that holds viruses and worms that invade your computer. It is named after the large wooden horse that the Greeks used to win the Trojan War. They climbed into the horse and entered the town of Troy disguised and leaped out to surprise the opponents. The computer form has the same effects and actions.
A blended threat is a combination of all the characteristics of viruses, worms, Trojan Horses, and malicious code to cause an attack. By using multiple methods of attack, blended threats can cause widespread damage and spread quickly.
An antivirus is computer software used to remove computer viruses, as well as many other types malware. The first antivirus software was designed to combat computer viruses, but most modern antivirus software can protect against a wide range of malware, including worms and Trojan horses.
A hacker is an individual who gains unauthorized access to a computer system for the sole purpose of stealing and corrupting the data found there.
Malware is short for malicious software, computer software that is designed specifically to damage or disrupt a system or computer, such as a virus or a Trojan Horse.
Spyware is computer software that is installed onto a computer without the user's consent to take partial control over the computer and "spys" on their personal information such as Internet habits or even worse--their passwords that they enter on the computer.
Adware is advertising-supported software that plays, displays, or downloads advertisements. A example of this are pop-up ads that happen when certain web sites open a new window to display annoying advertisements.