“GGUF has the same type of layout as GGML, with metadata and tensor data in a single file, but in addition is also designed to be backwards-compatible. The key difference is that previously instead of a list of values for the hyperparameters, the new file format uses a key-value lookup tables which accomodate shifting values.”
https://vickiboykis.com/2024/02/28/gguf-the-long-way-around/