What are Weaviate modules and how do they extend the database?

Weaviate modules are plugins that add capabilities like vectorization, reranking, generative search, question answering, named entity recognition, and image classification to the database. Modules run inside or alongside Weaviate and are configured per collection, so one collection might use OpenAI embeddings while another uses a local Hugging Face model. The text2vec modules automatically embed text at ingest and at query time, eliminating client-side embedding code. Modules make Weaviate a more integrated AI platform than pure vector databases.