# Data Structures

- [NFT](/artinals-protocol/art20/markdown/nft.md)
- [CollectionCap](/artinals-protocol/art20/markdown/collectioncap.md)
- [UserBalance](/artinals-protocol/art20/markdown/userbalance.md)
- [TokenIdCounter](/artinals-protocol/art20/markdown/tokenidcounter.md)
- [Dual IDs](/artinals-protocol/art20/markdown/dual-ids.md)