Glossary — Language models
System prompt
A system prompt is the hidden instruction a provider gives the model before your conversation starts, setting its tone, limits and role.
2 tokensSystemprompt
Simply put#
Before you type anything at all, the model has already been told who it is and how to behave. You never see that text, but it shapes every answer.
Example#
If you build your own AI solution, the system prompt is where the company rules go: what tone to use, what never to promise, when to say "I don't know".
Why it matters to you#
It is by far the cheapest way to steer behaviour — reach for it long before fine-tuning.