Prompt

A prompt is the input that shapes a model response. In an application it may include system instructions, a user message, examples, retrieved evidence, tool descriptions, and formatting rules.

Prompt engineering focuses on writing and organizing the task instructions and examples. Context engineering selects and maintains the broader working set supplied for the call. The prompt is part of that context.

Tiny example

Task: Answer only from the evidence.
Evidence: Refunds are allowed within 30 days.
Question: Can I return an item after 14 days?

What it is not

A prompt is not a security control. A model can misunderstand instructions, and untrusted content can conflict with them.

FDE note

Version prompts like code, test them against a stable evaluation set, and keep authorization and data-access decisions in deterministic application logic.