The Core, composed of ItemMainInterface and ItemInteroperableInterface contracts, represents the base of the Items protocol.
The Main Interface is the ERC1155 interface shared by all Items (all items have the same ERC1155 address).
The Interoperable Interface is the ERC20 interface of an Item and it's different for each Items (each Items has a different ERC20 address).
Be sure to read the Main Interface and Items Collections and Main Interface and Interoperable Interface section first to get a complete understanding of how Items works.
Learn about the ItemMainInterface, a singleton contract shared by all Items, native and wrapped, serving as their default collective ERC1155 interface.
Learn about the Interoperable Interface, one of which each Item has, serving as their unique ERC20 interfaces.