Milvus is an open-source vector database that supports eight types of Indexes to optimize data querying and retrieval. These include FLAT, IVF_FLAT, IV_SQ8, HNSW Index, IVF_PQ, ANNOY, BIN_FLAT, and BIN_IVF_FLAT. Each Index type is best suited for specific scenarios based on factors such as data dimensions, dataset size, search efficiency requirements, and available resources. Choosing the right Index type can significantly improve search performance in AI applications.