What is the difference between prompt.md and instructions.md in VSCode?

Personal Understanding

prompt.md

The prompt used in the copilot chat window, applied during conversations—for example, setting it to make Copilot reply in Chinese.

If not configured, Copilot will think and respond in English by default. You’ll frequently need to tell it: respond in Chinese

For more information, see 如何配置vscode copilot prompt提示词

instructions.md

Prompts specifically tailored for certain projects or programming languages.

Example below defines code generation standards for TypeScript and TSX files:

---
applyTo: "**/*.ts,**/*.tsx"
---
# Project coding standards for TypeScript and React

Apply the [general coding guidelines](./general-coding.instructions.md) to all code.

## TypeScript Guidelines
- Use TypeScript for all new code
- Follow functional programming principles where possible
- Use interfaces for data structures and type definitions
- Prefer immutable data (const, readonly)
- Use optional chaining (?.) and nullish coalescing (??) operators

## React Guidelines
- Use functional components with hooks
- Follow the React hooks rules (no conditional hooks)
- Use React.FC type for components with children
- Keep components small and focused
- Use CSS modules for component styling

For more information, see 如何配置vscode copilot项目提示词