What is the difference between RAG-fusion and HyDE?

RAG-fusion and HyDE are two advanced techniques within the Retrieval Augmented Generation (RAG) framework, each designed to enhance the retrieval and generation capabilities of language models. 

While both RAG-fusion and HyDE aim to enhance the performance of RAG systems, they do so through fundamentally different methodologies—one through aggregation of multiple retrievals and the other through innovative document generation based on hypothetical answers.