What is ERC20 vs ERC721?

Could you please elaborate on the difference between ERC20 and ERC721? I'm particularly interested in understanding how they differ in terms of their function, usage, and significance within the cryptocurrency and blockchain ecosystem. ERC20, as I understand, is a standard protocol for tokens on the Ethereum blockchain, enabling interoperability and compatibility among various tokens. On the other hand, ERC721 seems to be focused on non-fungible tokens, emphasizing uniqueness and individuality. Could you provide a deeper insight into these two standards and their respective applications? Thank you for your time and expertise in this matter.