Retrieval augmented generation (RAG) is a method to enhance large language models (LLMs) by integrating external, private data with their responses, addressing challenges like data limitations and inaccuracies. RAG leverages semantic search to retrieve relevant information based on meaning rather than keywords, using vector embeddings to represent concepts in a multi-dimensional space. This approach allows chatbots to generate accurate and contextually relevant answers without needing to access or train on proprietary data. The technique involves careful prompt engineering, including system prompts, supplied context, and user input, to ensure the LLM uses the retrieved data effectively. Elastic's platform, including Elasticsearch and its AI Playground, offers tools to implement RAG, making it feasible for businesses to create scalable, practical chatbot applications tailored to their specific data needs.