The model is fixed; the input is your lever
You rarely get to retrain a large language model, but you fully control what you send it. Prompt engineering is the discipline of using that control well: stating the task plainly, giving the model the context it needs, showing a worked example or two, and specifying the format you want back. Small changes in wording can move results from useless to excellent.
- Be specific — name the role, the task, the audience and the output format.
- Show, don't just tell — a couple of examples often beats a paragraph of instructions.
- Give it the facts — supply the source material rather than hoping the model remembers it.
Prompting has limits: it cannot give a model knowledge it never had. When answers must be grounded in specific or current information, you pair it with retrieval-augmented generation so the right context is in the prompt to begin with.
