A prompt is the input a person gives an AI — the question, request, or instruction it responds to. In AI search it plays the role the keyword query played in traditional search, but it's typically longer, more specific, and phrased as a full natural-language question.
That difference matters for visibility. Where old search tracked a handful of high-volume keywords, the prompts buyers type are long-tail and varied — "which moisturizer is best for sensitive skin in a dry climate?" rather than "best moisturizer." The model often expands a single prompt into several sub-questions before answering — see query fan-out.
For brands, the takeaway is to think in real questions, not keywords. The content that wins is the content that answers the actual prompts your customers ask — including the comparisons, conditions, and "is this right for me?" follow-ups that a keyword list never captured.
