A Familiar but Misunderstood Term
Almost everyone has heard of a computer virus, and the phrase usually brings a sense of worry. We are told to protect our devices from viruses and to be careful what we click. But many people are not quite sure what a computer virus actually is. It is not a living thing, and it cannot make a machine physically ill. So what is it really?
A Program, Just a Harmful One
At its core, a computer virus is simply a computer program, a set of instructions, like any other software. The difference is its purpose. A virus is a kind of harmful software, often called malware, short for malicious software. It is created deliberately by someone to do unwanted things on a computer, such as damaging files, slowing the machine down, or interfering with how it works.
Why It Is Called a Virus
The name comes from a comparison with viruses in biology. A biological virus spreads by entering a cell and using it to make copies of itself, which then infect more cells. A computer virus behaves in a similar way. Its defining trait is that it can copy itself. It attaches its code to other programs or files, and when those are run, the virus makes more copies, allowing it to spread from file to file and from computer to computer.
How Viruses Spread and Cause Harm
A virus needs a way to travel between machines. It might spread when an infected file is shared, when a risky link is clicked, or through email attachments. Once active on a computer, a virus can do various harmful things, from deleting or corrupting files to making the computer slow or unstable. This is why people use antivirus software, which is designed to detect and remove these harmful programs before they can spread or cause damage.
Source
This article was written using information from Wikipedia.