Retrieval-augmented generation (RAG) is a method used to enhance the accuracy and relevance of outputs from models like GPT-4 and Llama 2 by providing them with data from external sources beyond their initial training data. This approach helps prevent inaccuracies, known as hallucinations, by allowing models to access up-to-date and comprehensive information, leading to more reliable outputs. RAG also enables models to cite sources, offering users greater confidence in the responses and facilitating deeper exploration of topics. Various applications, such as sales automation and financial planning tools, benefit from RAG by integrating with systems like CRM and accounting platforms, allowing them to generate more personalized and insightful recommendations. Additionally, using platforms like Merge, which offer a unified API solution, can streamline the process of integrating external data sources, ensuring models consistently receive high-quality data while allowing developers to focus on refining model performance rather than data management.