According to the documentation:
An app is a Web application that does
something — e.g., a weblog system, a
database of public records or a simple
poll app. A project is a collection of
configuration and apps for a
particular Web site. A project can
contain multiple apps. An app can be
in multiple projects.
However, what are other examples of what makes an “app”?
What makes an app (for us) is one thing:
An App Is The Unit Of Reuse
If we might want to split it off to use somewhere else, it’s an app.
If it has a reusable data model, it’s an app. User Profiles: App. Customers: App. Customer Statistical History (this is hard to explain without providing too many details): App. Reporting: App. Actuarial Analysis: App. Vendor API’s for data gathering: App.
If it is unique and will never be reused (i.e., customer specific) it’s an app that depends on other apps. Data Loads are customer specific. Each is an app that builds on an existing pair of apps (Batch Uploads, and Statistical History)