adding to other user's definition of LangChain: LLMs have what are called "context" which is basically the amount of information it can remember at any one time

adding to other user's definition of LangChain: LLMs have what are called "context" which is basically the amount of information it can remember at any one time. GPT-3 it was about 2 pages of text, GPT-4 is currently about 6 pages of text and will soon be about 40 pages of text. If you want the LLM to know about more data than that, LangChain will allow you to "chain" together multiple contexts that the LLM can gather data across.