Difference between an app and its content

I was recently asked again about the difference of app and issue and I frequently see that people ask about “my app exported out of QuarkXPress”. So I thought it might be a good idea to explain the difference between the app itself and the content it displays (Quark calls this an “issue” and Adobe “folio”).

Imagine a DVD Player with DVDs:
A DVD Player can play different types of DVDs and each DVD can have different content. To see content (e.g. a movie) you need both, as the DVD Player by itself is kind of sad and a DVDs by itself cannot really reveal its content.

In the App Studio analogy the DVD Player is your app. And the DVDs are your issues (.zave files).

You create your app using App Studio Factory (that comes with the installation of QuarkXPress) and your issues (.zave) by exporting them out of QuarkXPress. And you need the Quark App Studio Publishing Portal to tell your app which issues to display.


Interestingly enough this analogy even works for the pricing model:
With Quark you pay once for the Player to be build (with your logo on it) and once for each DVD to be created.

Other vendors ask a yearly rent (or platform fee) for giving you as many DVD Players and DVDs as you want, additionally you have to pay each time somebody watches the DVD (called download fee).