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What is a prompt and how does it work

A prompt is the instruction you give an artificial intelligence. Learn its parts, why the result depends so much on how you write it, and how to get started.

A prompt is the text (and sometimes the image, audio or document) you give an artificial intelligence model to ask it for something. It can be a short question like “what is photosynthesis?” or a detailed brief of several paragraphs with context, examples and an output format.

In practice, the prompt is how you communicate with tools such as ChatGPT, Claude, Gemini, Midjourney or Runway.

Why the prompt matters so much

A language model generates the most likely response based on what you give it. It does not know your company, your audience or your preferences unless you tell it. That is why two people asking “write me an email” get very different results depending on the context they provide.

A good prompt reduces ambiguity: it tells the AI what to do, for whom, with which information and how to present the result.

The parts of a prompt

Not every prompt needs every part, but knowing them helps you write better:

  • Role: the perspective it should answer from (“act as a newspaper editor”).
  • Goal: the specific task you want to accomplish.
  • Context: background information the AI cannot guess.
  • Instructions: steps or criteria to follow.
  • Constraints: what it must not do, or limits (length, tone, topics).
  • Output format: table, list, JSON, email, code…
  • Example: a sample of what you expect.

You can practice with our prompt builder, which guides you field by field.

A simple example

Vague prompt

Write a post about coffee.

Clear prompt

Write an Instagram post (max 120 words) for a neighborhood coffee shop introducing its new Colombian coffee. Audience: locals aged 25-45. Friendly tone. End by inviting them to try it this week with 10% off.

The second prompt is not “magic”: it simply gives the information a person would also need to do the job well.

Prompt types by tool

  • Text (ChatGPT, Claude, Gemini, Copilot): conversations, writing, analysis, code.
  • Image (Midjourney, DALL-E, Stable Diffusion, Flux, Firefly, Ideogram): visual descriptions of subject, style, light and composition.
  • Video (Runway, Kling, Sora, Veo): one shot with subject, action and camera movement.
  • Audio (Suno, ElevenLabs): music style, lyrics or voiceover text.

What a prompt cannot do

A good prompt greatly improves the result, but it does not make the AI infallible. Models can be wrong or invent data with great confidence. Always review important information, especially figures, quotes, dates and legal, medical or financial topics.

Next step

Read how to create a prompt from scratch or explore the prompt library to see real examples you can copy and customize.

Learn prompting