Chapter 8

1. The ERC165 standard is used in the ERC721 standard so that it knows which functions are supported by the contract. Similarly, you can use the ERC165 standard in any other standard or contract to let the client know about the functions supported by the standard or the contract.
2. The ERC721 NFT standard should be used when you have some digital assets that are nonfungible. Nonfungibility means that you cannot further subdivide these assets. As an example, digital collectible cards are nonfungible, and each one is different from others.
3. The _mint() and _burn() functions are both internal functions, and so these can be called from the implementing contract. The _mint() function is used to create a new, unique ERC721 NFT token and send it to the given address. On the other hand, the _burn() function is used to burn a given NFT...