What is Pinecone and what is it used for?

Pinecone is a managed vector database service for storing and searching high-dimensional embeddings at scale, used primarily for semantic search, recommendation, and Retrieval-Augmented Generation. It handles indexing, sharding, replication, and backups automatically, exposing a simple REST and gRPC API for upsert, query, and delete operations. Pinecone supports metadata filtering, hybrid sparse-dense search, namespaces for logical separation, and serverless or pod-based deployment. It integrates with LangChain, LlamaIndex, and major cloud providers including AWS, GCP, and Azure.