1. Series Designation: The TC58BYG2S0HBAI6 belongs to the Benand™ series, while the TC58NYG2S0HBAI6 carries no series label. Benand™ is a proprietary Kioxia technology, typically indicating the NAND integrates an internal ECC engine and firmware-level functions such as bad block management. The BYG variant likely offers more advanced self-management capabilities, placing fewer demands on the host controller. In contrast, the NYG variant may represent a more basic, raw NAND die, requiring the external host controller to implement full management. 2. Functional Level Disparity: This distinction suggests a potential difference in "intelligence" between the two parts. The BYG model is better suited for designs seeking simplification or for systems with host controllers possessing limited ECC capability. The NYG model requires pairing with a host controller that has robust NAND management features. If the system's host controller already provides comprehensive NAND management, the two devices can be considered hardware-compatible substitutes. 3. Cost and Supply Chain Considerations: The price difference likely stems from the added value of Benand™ technology or variations in production batches and market positioning. When considering substitution, beyond verifying basic electrical compatibility, it is essential to confirm complete alignment in command sets, internal architecture, and reliability metrics by consulting the official datasheets.