With the rapid development of artificial intelligence technology, more and more applications are beginning to enter our lives. Retrieval-Augmented Generation (RAG) is an emerging technology and is gradually becoming an important tool in the field of natural language processing. Many people may be unfamiliar with the concept of RAG, but it has great potential in improving the accuracy and practicality of generative AI. This article will deeply analyze the operating principles, advantages and practical applications of RAG, so that novices can easily master this technology.