Step 1: Classification of assets.
- Current Assets: Cash, stock, debtors, etc.
- Liquid Assets: Readily realizable assets like cash and bank.
- Intangible Assets: Non-physical assets like goodwill, patents, trademarks, copyrights.
Step 2: Identify patents and copyrights.
Patents and copyrights are legal rights, non-physical in nature, and generate future economic benefits. Thus, they are intangible assets.
Step 3: Conclude.
Hence, patents and copyrights are classified as Intangible Assets.
Final Answer:
\[
\boxed{\text{Intangible Assets}}
\]