2023-arxiv Retrieval-Augmented Generation for Large Language Models-A Survey
Introduction
The paper mainly introcude the solution for optimizing the RAG system, and the evaluation framework&tools are also included, which can be seen as below:

More specifically, three paradigms of RAG are demonstrated as followings:


The ecosystem of RAG can be seen in the img below:

2023-arxiv Retrieval-Augmented Generation for Large Language Models-A Survey
https://firrice.github.io/posts/2024-06-26-RAG-survey/