Why an LLM alone is not enough

An LLM may have broad knowledge, but a real organisation often needs answers based on specific, private, recent, or approved information: 

• A school’s current handbook 
• A hospital’s internal procedures 
• A company’s product documentation 
• A climate course’s official book 

Retraining a large model whenever one paragraph changes would be slow and expensive. A RAG system takes a more practical route: keep the documents in a searchable library and place relevant excerpts into the prompt when needed.