Coders I don't understand how to transform css or phyton or php into an app

Answer 1

There is no transforming. There is no one file or package to be the application.
The internet application today is a large amount of files, different types. A html, css at first. And files of pictures, And for dynamic applications php or phyton or asp -but it depends of type web server and its used moduls..
So, not transforming, but a good organization of these files in particulary folders and sunbfolders, connected the right way.

Answer 2

#petr, suppose an app like amazon or eBay , where or which code did php create. where can you point out that here is the work of php or javascript?