What is Antivirus software? Getting started with PC security

As our lives become more and more digital, keeping our information and devices secure has become more important than ever. And that starts with good security software. An antivirus program is a piece of software that keeps your computer (or phone, tablet, etc.) safe from other software that tries to attack it. This includes detecting and blocking viruses, a very specific type of program, but also a wide variety of other digital threats.

PCWorld is constantly covering the latest news in viruses and other threats, and how to defend against them. For the best antivirus software in 2023, be sure to check out our extensive roundup of the best antivirus programs.

What is a computer virus?

To understand what antivirus software does, you need to know what a computer virus is. “Virus” in this context has a broad definition, but to put it simply, it’s a program that gets installed on your computer, then automatically spreads itself to other computers across a network or the internet, mimicking the spread of a biological virus spreading through an organism’s cells.

What precisely a virus does depends on the specific virus, but it’s never good. In the early days of personal computers, a lot of viruses were designed merely to damage your computer for the sake of pure mischief. The famous “ILOVEYOU” virus spread through email downloads and merely overwrote files on the hard drive with junk data, until the computer became unstable and had to be completely wiped.

Then there are viruses designed to take remote control of your computer, often without you realizing it, in order to create a secret network called a “botnet.” Botnets like MyDoom can be used to spread spam or scams, or attack other computers with distributed traffic designed to shut down web services.

Dominik Tomaszewski / Foundry

But the most insidious and personally dangerous type of virus, and the more common one in the modern world, is designed to steal from users themselves. This can be done several ways. A “spyware” or “spybot” program searches the files on your computer for your personal information like login passwords or bank accounts, while “ransomware” locks…