The Desktop is a way of organizing a complex set of business activities. There are 3 levels: application, workspace, and activity. Each application represents a business category. Each workspace represents a type of data within that business, and each activity represents an action you can perform on that data.

For example, if you were to write software for writing novels, you might have 3 workspaces: one for character biographies, one for notes, and one for the actual story. The workspace for character biographies would have an activity that lists characters where you could add, edit, or delete characters. Editing a character in this list would open up a new activity within that same workspace where you could edit the character.