Scott provided a pretty good summary, but let me expand on it.
With Enterprise, the assumption is that your core project is a Corona SDK project that you could run in a simulator, build, run etc. But now you need to expand features that we currently don’t support. You find some native library that you want to include. This is where Enterprise shines. You create whatever native bindings, and then call your native libraries from your core Lua based code, much like you do with plugins. In addition, Enterprise lets you make plugins. It provides offline builds and the ability to script your build process and do more automation.
CoronaCards on the other hand is the opposite of this. CoronaCards assumes you have an existing native app where so far everything has been done in native land but you want to add a feature to your native app that Corona would be good for. You basically create a view in your native app (could be full screen, or a window inside the app) that opens up and runs Lua/Corona code in the view. Maybe you have a business/utility app and you want to offer a game inside it.
But this is one of the reasons why we are asking these questions. People might not be using CoronaCards the way we understand and before we go making changes. As our new CEO Stepan posted in the sister thread on Enterprise (https://forums.coronalabs.com/topic/68395-how-do-you-use-corona-enterprise/) we really would like to know more about how CoronaCards is used in your projects and business.
Right now our survey linked in the other thread is Enterprise related, I’ll see about getting a Cards specific survey made, but for now just let us know here about your use of CoronaCards.
Rob