KDP is Kindle Direct Publishing. It is Amazon’s publishing platform. Originally, it was split into Kindle Direct Publishing (ebooks) and Createspace was a separate entity, that could be connected. Recently (2017), Amazon added a Beta paperback program in KDP’s platform.
KDP does not require exclusivity unless you use KDP Select.
See also KDP Select, DRM, Paperback (beta), ISBN, AISN.