What is the difference between zero-shot, few-shot, and fine-tuning?

Zero-shot: no examples in the prompt, relying on the model’s pre-trained knowledge. Few-shot: include 2-10 input/output examples in the prompt to guide format/style. Fine-tuning: actually update model weights on hundreds to thousands of examples. Start with zero-shot, then few-shot, then fine-tuning in that order; each step is more costly.