Retrieval
Useful context often comes from finding the right external material.
Retrieval is finding relevant information from an external collection in response to a query. Its output can be documents or passages that an application supplies to a model.
[LangChain]In practice
A help desk searches product manuals and returns the passages most relevant to a customer’s error message.
[LangChain]A little deeper
Retrieval is a search step. Combining its results with generated answers creates a broader system; the retrieved passages alone are not that generated answer. [LangChain]
A common mix-up
Retrieval and generating an answer are the same operation.
Retrieval returns material; generation uses input to produce a response. [LangChain]