Spending too much time on the internet is not really a good thing. But if you cannot help it or your work depends on it, you might as well learn how to be cautious. There are many internet threats if you just click the wrong link or visit the wrong website.
Sure, there are antivirus and anti-malware available for downloads. Even the free version ones are as effective as the other paid ones. But you should remember that no antivirus is perfect. Sadly, even the best malware-detecting app you have installed can be bypassed no matter how updated you make it.
Know the internet threats
Now, if by some bad luck your computer happens to get infected by a malware, you should at least learn what they can do to your operating system. Some malware does not just disable some of your computing abilities but also spy on you. So try to read as much as you can and learn if the one that got your computer is one of the lesser things you should worry about or the worst.