What is a Computer Virus?

Viruses have been around for over forty years starting in 1971, the Creeper , the first computer virus, ushered in an era of malicious software or "malware." These pests include viruses as well worms, Trojan horses, spyware, scareware, ransomware, phishing and more, all colorfully named but seriously dangerous. Attacks have changed from mere pranks to costly criminal acts.(Greenberg 29)
Viruses can be very harmful to your computer. It is extremely important to know exactly what you are getting from the internet. New viruses are being created all the time. You might ask “what exactly is a virus?” Dr. Alan Solomon describes:
A virus is a program that copies itself. That's the definition of a virus. In retrospect, it's unfortunate that the word `virus' was used; it makes the problem sound a lot worse than it is, and people get the plural wrong [the plural is not `viri', or even `virii', it's `viruses']. It might have been better to use the word `weed'. But we're stuck with `virus'.
A virus need do no more than replicate in order to be a virus. Indeed, 95% of viruses do no more than that, plus some trivial extra like beeping the keyboard, or displaying a message. And conversely, if a program does something nasty that you weren't expecting, that doesn't make it a virus, unless it replicates. Such a program is called a `trojan', after the famous horse of Troy.(Solomon )
A Trojan horse is thought by most to be a virus; however, it does not replicate as a virus would.
Every computer user is susceptible to a computer virus. Studies show that an unprotected computer can be infected by a virus within minutes after being connected to the internet. (Shelley 178)
A good antivirus is very important for your computer as there are many different viruses and other malware out there with