System Prompt
Hidden background instructions that set an AI's behavior, tone, and rules before you type anything.
01 Definition
A system prompt is a set of instructions given to an AI model behind the scenes — before your conversation starts — that shapes how it should behave, what persona it should take, and what it should or shouldn't do, separate from your actual messages.
02 Why It Matters
This is why the same underlying AI model can feel very different across products — a coding assistant and a customer-support bot might use the same base model with very different system prompts.
03 Example
A company's support chatbot might have a system prompt saying 'Only answer questions about our product, always be polite, never give legal advice.'