What exactly is a computer virus? How to avoid it?

We all know what computer viruses are, or we at least know a short and easy description of them.  Most people refer to them as "computer viruses, malware, and PC Infections". But what actually defines a computer virus?

A computer virus is a program that looks normal and looks like it does normal things, such as an auto clicker for your favorite video game, but actually does things that you don't know about, "behind the scenes". You may not notice these things until later on, and you may notice that your PC is slower, your CPU is always at 100%, your ram is always at high usage, or your computer is just acting weird in general. This may be due to the virus creators using your PC as a "bitcoin miner". They use your PC to mine for bitcoin which requires them to hog all of your PC resources.  You should always have an antivirus, and if you need a decent one for free we recommend Avira Free Antivirus. If you notice any of the things we mentioned before, you should definitely consider scanning your PC with an antivirus. Computer viruses spread like viruses in real life, they can get from one computer to another from simply plugging in a USB to the infected computer, then it creates a hidden autorun file to do something when plugged in, and once you plug it into another computer, that computer gets infected too. It is like when you share a drink in real life, you are spreading germs to one another.  Computer viruses do not naturally exist, they are created by people to intentionally hurt your PC. Some people do this, and demand money to remove the virus from your computer and unlock your files. This is called ransomware. Thousands of people are infected by ransomware every year and even every month.