Enterprise RAG refers to retrieval-augmented generation run inside an organization, against its own documents and records, under its own access rules. The retrieval mechanism is the same as any other RAG system. What differs is everything around it: who is allowed to see which passage, how often the source changes, and whether an answer given last quarter can still be accounted for.
Three constraints separate it from a demo. Permissions have to survive retrieval, so a passage a user cannot open in the source system must not reach them through the model either. The corpus keeps moving, so an index built last month answers from a version of the business that no longer exists. And evaluation cannot be a spot check, because the same question asked twice should not return two different answers without an explanation.
There is an earlier constraint that appears before any of this. Some of the records an organization would most want to index cannot be sent out in their original form at all, so they are left out of the corpus and the system answers from whatever remains. Masking the sensitive fields lets the documents through, but it also removes the table structure and the relationships between business identifiers that made those records worth retrieving. Deciding what enters the index, in what form, is part of designing enterprise RAG rather than a step that comes after it.