INDD files versus INDDC files versus INDDL files

Hey gang,

Help me get this straight, please, as I experiment with newer things:

An INDD file is operated within the InDesign application on desktop. OK, I know that.

An INDDC file is an InDesign file converted to be stored in the Adobe Cloud. Is that the same as what you put into a Project folder? For sharing?

But what about Share for Text Editing? Is there now a 3rd InDesign filetype? What is an INDDL file? Only for collaboration with the awkwardly-named “InCopy on the web (beta)? 

Are there 2 cloud-based versions of the InDesign document?

How does anyone accomplish any version control with this arrangement?