IntroductionI will be discussing the topic of ERC-721 smart contracts and specifically, the ERC-721A contract. The Ethereum Request for Comments (ERC) 721 is the standard for creating non-fungible tokens (NFTs). As the name suggests, NFTs are unique and cannot be replaced by another token. In contrast, fungible items such as Bitcoin, US dollars, and gold are interchangeable. The ERC-721 was proposed in January 2018 by William Entriken, Dieter Shirley, Jacob Evans, and Nastassia Sachs. Since t...