This is a good course for studying Langchain RAG. However, you need to have an understanding of natural language processing concepts such as embedding, tokenization, and cosine similarity to easily understand it, and the visualization of the RAG operation process using LangSmith was impressive. However, although you provide various options in many different ways, it would have been better if you had explained in more detail how to apply the differences and uses of functions that might seem similar in practical work. There were often cases where I had to ask AI questions or search through Google to get additional information I was curious about. But I think the Langchain RAG course is the most excellent course I've seen on Inflearn.