AI Glossary Term
What does “System Prompt” mean?
Definition
A high-priority instruction that sets behavior, policy, and response style for a model.
How System Prompt works
Example
A travel company's assistant has a system prompt saying 'You are a friendly booking helper; never share other customers' information; answer in English'. Users do not see it, but it shapes every reply.
Why it matters
It sets the model's role, tone, and limits. It is not a perfect security boundary, since users may try to override or extract it.
Common questions
Can users see it?
Often not, though it can sometimes be coaxed out, so secrets should not be placed in it.
Is it the same as a user prompt?
No. The system prompt is set by the application; the user prompt is what the person types.
Does the model always obey it?
Mostly, but conflicting or manipulative user input can sometimes override it.