RAG & Knowledge

RAG Explained: How AI Agents Use Your Company's Data

Retrieval-Augmented Generation lets AI agents pull real answers from your documents and systems. Here's how it works in practice.

Coeus Learning · 8 min read · March 2026

If you've ever asked ChatGPT a question about your company and received a confidently wrong answer, you've experienced the fundamental limitation of standard AI: it only knows what it was trained on. Your company's documents, policies, customer data, and internal knowledge? It has no idea.

RAG (Retrieval-Augmented Generation) solves this. It gives AI agents the ability to look up real answers from your actual data before responding.

RAG in one sentence

RAG lets AI agents retrieve information from your documents, databases, and systems — so they give accurate, grounded answers based on your actual company data, not just general training knowledge.

The library analogy

📚

Without RAG

Imagine asking a very intelligent person a question about your company. They're smart, articulate, and confident — but they've never read any of your documents. They'll give you an answer, but it might be wrong, outdated, or completely made up.

🔍

With RAG

Now imagine that same person has access to your company library. Before answering, they walk to the shelf, pull the relevant documents, read them, and then answer your question — citing the source. That's RAG.

How RAG works — four steps

1

Ingest

Your documents, databases, and files are processed and converted into numerical representations (embeddings).

2

Store

Embeddings are stored in a vector database — a specialised system optimised for similarity search.

3

Retrieve

When a question arrives, the system finds the most relevant chunks of your data.

4

Generate

The AI model uses the retrieved context to generate an accurate, grounded answer.

See it in action

Customer support agent with RAG

Customer: “What's your return policy for electronics?”

AI agent (with RAG): “According to our returns policy (updated January 2026), electronics can be returned within 14 days of purchase in original packaging. A restocking fee of 10% applies for opened items. Would you like me to start a return for you?”

Internal knowledge agent with RAG

Employee: “What's our approval process for purchases over $5,000?”

AI agent (with RAG): “Per the Finance Policy v3.2 (section 4.1), purchases over $5,000 require department head approval, followed by CFO sign-off within 48 hours. The request form is on the intranet under Finance > Procurement.”

Want to give your AI agents access to your company's knowledge? We build RAG-powered systems that turn your documents into actionable intelligence.

Book a Strategy Call

RAG vs fine-tuning

These are the two main approaches to making AI “know” your data. They serve different purposes:

RAGFine-tuning
What it doesGives AI access to your data at query timePermanently changes the AI model's knowledge
Data freshnessAlways current (reads live data)Frozen at training time
CostLow — no model training requiredHigh — requires GPU compute and expertise
Setup time1-2 weeks2-8 weeks
Best forCompany knowledge, documents, FAQsSpecialised language, domain terminology
Can combine?Yes — RAG + fine-tuned model is the gold standardYes

Frequently asked questions