What is key value?

NVM Express Base Specification Features

The NVMe Key Value (KV) Command Set has been standardized as one of the new I/O Command Sets that the NVMe specification supports. NVMe-KV allows access to data on an NVMe SSD controller using a key rather than a block address. The NVMe-KV Command Set provides the key to store a corresponding value on non-volatile media, then retrieves that value from the media by specifying the corresponding key. NVMe-KV allows users to access key-value data without the costly and time-consuming overhead of additional translation tables between keys and logical blocks.