RAG-Graph combines retrieval-augmented generation with knowledge graphs so LLMs can reason over explicit entities, relationships, and constraints instead of only free text. It synchronizes a graph database and a vector store, then orchestrates hybrid retrieval (semantic + graph queries) before prompting the model. This enables multi-hop reasoning, better disambiguation, and auditable explanations in domains where relationships matter as much as content. The pattern is especially useful when you need both rich semantic recall and precise, explainable reasoning over structured knowledge.