What is a vector database?

Answer

A vector database stores and searches high-dimensional vector embeddings, the numeric representations of text, images, or other data produced by machine learning models. Instead of exact matching, it finds the nearest vectors by similarity using approximate nearest neighbor (ANN) algorithms such as HNSW, enabling semantic search. They are central to AI applications like retrieval-augmented generation (RAG), recommendation systems, and image search. Options include dedicated stores like Pinecone, Milvus, Qdrant, and Weaviate, as well as vector extensions for existing databases such as pgvector for PostgreSQL.