It's also possible to select different PHP "execution modes" for each site at Virtualmin > Server Configuration > Website Options - I recommend FPM because it's significantly faster and uses less memory. I've found that the default settings sometimes result in excessive memory usage, which can be avoided by adding the following settings to Virtualmin > Services > PHP-FPM Configuration, which limit the lifetime of processes if a site has a memory leak:

The most obvious and popular reason for a VPS is to run a single website, or multiple websites. However, you can use them for pretty much anything that requires access to the internet – such as a web application like Nextcloud to run your own Dropbox alternative – or to create your own virtual private network to better secure the internet connection of your PCs and mobile devices.