Large language models (LLMs) like GPT and Llama have transformed technological interactions, but their limitations in accuracy and context retention have led to the development of Retrieval Augmented Generation (RAG). RAG enhances LLM performance by integrating external retrieval systems that provide contextually relevant and updated information, akin to a student consulting a textbook during a test. This method involves two key components: a retriever that locates pertinent data using techniques like dense retrieval and semantic search, and a generator that crafts coherent responses based on this data. While RAG offers advantages such as reduced training costs, enhanced scalability, and access to diverse knowledge sources, it also faces challenges including potential inaccuracies, scalability issues, and biases in data retrieval. Despite these challenges, RAG's application across industries like healthcare, finance, and customer support demonstrates its value in providing precise, real-time information, thereby enhancing decision-making and interaction quality.