Cursor Rules allow you to define custom instructions that guide AI behavior in your projects. Create a .cursorrules file defining coding standards, architectural patterns, library preferences, naming conventions, and project-specific context. The AI respects these rules across all interactions, ensuring consistency with your team's practices. Features include project-level rules, team sharing, pattern enforcement, and best practice guidance. Particularly valuable for teams wanting AI assistance that follows their specific standards. Can include instructions about frameworks, testing approaches, documentation style, and architectural decisions. Transforms Cursor from generic AI to your team's AI.