Can someone clearly explain what the benefits of chains are?

[miketikh]

Let's say for example you were building a document Q&A, you can structure it using:

• Multiple LLM / Chat model calls using functions (summarize document, store document, queryDocument) then call them sequentially
  OR
• You can make all these calls into a chain

Having read and watched several guides to chaining, I still can't understand the clear value they add over just doing separate calls and feeding the input into the next call. What am I missing here?

[iway1]

If you're doing a simple chains as you described there's not really much if any benefit to using the library.

I think it becomes more useful when you start to leverage its memory APIs IE https://js.langchain.com/docs/modules/memory/examples/buffer_memory_chat, and if you start to leverage more APIs in the library like output parsing.