You have the older version CS6 and the new version CC. What is the problem here? Not 2 kinds, 2 versions, version 8 and version 9.
You can also download the other programs as CC.
Adobe InCopy is the little brother of InDesign, you can export content of InDesign in InCopy files, the InCopy user will be able to edit content but not geomety, mostly they will be able to edit text when they check out the text, they will see the layout but cannot access to the design.
It is mostly used in redactionw when the journalist write on the same document which is the designer working at at the same time.
InCopy has a lot more of text functions in the perspective of editing content than InDesign.
Both, InDesign and InCopy are technically spoken plugin manager from the same kind with different plugins to use.