As we did in the previous recipes, we can take a look inside the playground to see how each playground page is represented. Right-click on the playground, or hold Ctrl while clicking on it; from this menu, select Show Package Contents:
You will see that the Contents.swift that we saw earlier has been replaced with a folder containing three .playgroundpage files, one for each page in the playground:
Each of these .playgroundpage files is essentially a playground in itself. You can right-click on the .playgroundpage and select Show Package Contents, and you will see the same playground structure that we saw previously. Much like the normal playground, a .playgroundpage file can contain the Sources and Resources subfolders, and placing code and resources in these will make them visible to just that page.