Beware when searching around on the internet. Computer viruses come in many forms and each one has a clever way of tricking you into giving them access to your device.
Computer viruses are able to attach itself to a program or file, enabling it to spread from computer to computer, like a human virus. Viruses can range in severity, from mildly annoying to hardware-destructive. Viruses cannot be spread without human action.
Worms are a sub-division of viruses. The worst thing about worms is their ability to spread without any human action. Worms can multiply and send hundreds or millions of copies to your contacts and to their contacts. This rapid spread can slow down bandwith and cause web servers to crash.
Trojan Horses disguise themselves as legitimate software or files in order to trick the user into running the program. Like viruses, trojan horses can either be mildly annoying, or cause serious damage to your system. Trojans are also known to create backdoors on your computer to let malicious users gain access to all of your information. Trojans do not self replicate or reproduce by infecting other files.
Some ways to prevent getting viruses on your computer is to install Antivirus software, always have the latest security updates, and never click on anything that seems suspicious or sketchy.