Today computers are under constant threat. Antivirus software can help keep computers clean of certain types of malware. Antivirus software is not foolproof, it only matches known software and often notifies you when the software is already on your computer.
The way antivirus software generally works is it looks for the fingerprint of software known to be viruses and malware and removes that software from your machine. The virus scanners generally will not recognize software that has been modified, but will stop many known threats.
There are a number of antivirus software that I have used for home use. Windows 10 comes with Defender which has been scoring pretty well on tests. There is a free virus scanner Avast which I currently recommend. It will bug you to pay for it, but you can run it for free. Other people recommend Norton, McAfee, and Bitdefender which should all cost around $20.
The issue with some of these antivirus programs is that they can cause your computer to slow down since they are constantly scanning memory. I have run into issues where computers run exceedingly slow while running Norton and McAfee.
Even if you are running antivirus software you still need to avoid sites that are sketchy, don’t open things that you are not sure of and think defensively. Paying attention and not being very trusting are also necessary.
Many of the antivirus programs provide additional functionality of firewalls and email scanning. This functionality may be redundant and can be turned off. Usually the antivirus has a main status display where you can turn off any redundant functionality. If you are unsure of how to turn off an unwanted feature, I recommend performing an Internet search on how to accomplish this with your software.