Appropriate Protection From Viruses Worms, Trojans, Spyware

Not everybody is aware even nowadays about the differences between the terms Virus, Worms, Trojans and Spyware but only a few of us know what exactly separates these categories. The majority of the users believe that everything that is detected by their antivirus software is a virus, which is totally wrong.

An antivirus software not only detects viruses but also Trojans, Worms and Spyware. Another thing that every user should know is that a virus is not categorized as a malware and vice versa. Of course, all the above can be very harmful to our computers' hardware and software but there are numerous differences between a virus, a Trojan, a Worm and a Spyware. We will now analyze each category in order to clarify these differences:

Virus.
A computer virus is a computer program that can copy itself and infect a computer. The term "virus" is also commonly but erroneously used to refer to other types of malware, including but not limited to adware and spyware programs that do not have the reproductive ability. A true virus can spread from one computer to another (in some form of executable code) when its host is taken to the target computer; for instance because a user sent it over a network or the Internet, or carried it on a removable medium such as a floppy disk, CD, DVD, or USB drive. Once it enters into system memory it either searches for other files that can be infected or stays in the background and infect the files that are uses the virus infected program.

Worms.
A computer worm is a self-replicating malware computer program, which uses a computer network to send copies of itself to other nodes (computers on the network) and it may do so without any user intervention. This is due to security shortcomings on the target computer. Unlike a computer virus, it does not need to attach itself to an existing program. Worms almost always cause at least some harm to the network, even if only by consuming bandwidth, whereas viruses almost always corrupt or modify files on a targeted computer

Trojan Horses.
A Trojan horse, or Trojan, is software that appears to perform a desirable function for the user prior to run or install, but (perhaps in addition to the expected function) steals information or harms the system. The term is derived from the Trojan Horse story in Greek mythology.

Spyware.
Spyware is a type of malware that can be installed on computers, and which collects small pieces of information about users without their knowledge. The presence of spyware is typically hidden from the user, and can be difficult to detect. Typically, spyware is secretly installed on the user's personal computer. Sometimes, however, spywares such as keyloggers are installed by the owner of a shared, corporate, or public computer on purpose in order to secretly monitor other users.