RAG for external references versus fine-tuning for built-in behavior

Remember the core of choosing between RAG and fine-tuning.
・RAG (retrieval-augmented generation): References external, latest, frequently changing, or company-specific information and reflects it (no retraining needed). Example: search the latest product manuals or internal policies and use them in the answer.
・Fine-tuning: Builds repetitive behavior into the model itself, such as a fixed writing style, output format, classification, and technical terminology (updates the weights). Example: answer in the tone and standard format of the company's own support desk.
Options that reverse the roles or reverse the cost ordering are the classic traps. The two can also be combined.