Since Kirby is a flat-file CMS, pages that make up your website usually exist as files and folders in the filesystem. This has many advantages: your web project can be version controlled, you don't have to deal with a database, it's easy to make backups, you can manually edit your content if you want, and last not least, it's also very fast.
With the new architecture in Kirby 3 you can now combine our native, file-based pages with pages from any other data source – from databases, external APIs, Excel sheets – you name them.
We refer to any page that does not exist in the content folder as "virtual page".
All virtual pages are seamlessly integrated in Kirby. Routing works out of the box, they are included in API requests and they are even manageable in the panel!