Difference between CN & HS

The global harmonised system (HS) is the common international system for classifying goods – used for international trade negotiations for example, and applied by most trading nations. Run by the World Customs Organization, it uses 6-digits and is used worldwide.
The EU's combined nomenclature (CN) is based on the HD but uses 8–digit codes for a more detailed categorisation – which helps to give you clear, detailed information on your product.