If you want to learn more about RGB smart contracts, you can check rgb.tech and rgbfaq.com websites
RGB smart contracts interact with the world via interfaces providing API for wallets, exchanges and other software. They define types of assets and contracts, like tokens, NFTs, DAOs, identity etc.
Schemata are “templates” for creating smart contracts and issuing assets. They allow to separate the role of programmer from the role of contract and asset issuers and reduce risks in designing contracts.
RGB smart contracts are developed either in Rust by using RGB standard library - or with a specially-designed Haskell-like programming language called Contractum, which is currently in active development.