The LangChain framework enables developers to build chatbots that interact with language models and external sources of data or computation, using clear and modular abstractions for building blocks necessary to build applications. It focuses on simplifying the development process by providing commonly used "chains" that are combinations of the building blocks. The framework uses Redis as a vector database to store product metadata and OpenAI-generated embeddings, allowing chatbots to query the catalog for products that are most similar to or relevant to user queries. LangChain provides tools such as Conversational Retrieval Chain, LLM Chain, and question answering chain to create a conversational retail shopping assistant that can help users find products based on their preferences. The framework also allows developers to customize the BaseRetriever class to perform document preprocessing before returning results, enabling more product information to be infused into conversations.