Older versions of InDesign were designated with a CS, the most up-to-date version is designed CC.
CS was short for Creative Suite. So the most recent version of InDesign CS was InDesign CS6. These versions of InDesign were sold with the older perpetual licence type of access and are no longer supported by Adobe.
Creative Cloud is the description given by Adobe to all of their applications that are available over the internet.
The Adobe Creative Cloud is a collection of over 20 Adobe products.
These enable photography (Photoshop CC), design (Illustrator CC), video (Premiere Pro CC), movie effects (After Effects CC), and much more.
Apps accessed through the Adobe Creative Cloud are constantly upgraded and so the designation does not change as it used to with each new release of InDesign which went CS1, CS2 and so on.