Similarity vs Logic
**Vector Search** is great for "What is similar to this query?" It is fast and handles fuzzy matches well. **Graph Search** is great for "How is A related to B?" It is deterministic and handles complex multi-hop reasoning. In a modern agent, we often use both in a "Hybrid Search" approach.
The Hybrid Advantage
By combining vector and graph search, you get the best of both worlds: the broad retrieval of vectors and the precise relational logic of graphs. LangChain makes it easy to implement this hybrid pattern, ensuring your agents have the most powerful and versatile retrieval engine possible.
Conclusion
Retrieval is the foundation of reasoning. By understanding the strengths and weaknesses of vector and graph search, you can design the perfect intelligence architecture for your specific business needs and data types.