Hapi is a Node.js web application framework designed for building scalable server-side applications and APIs. The framework provides built-in functionality for common web development tasks including routing, input validation, caching, authentication, and error handling. It offers a configuration-centric approach where developers can define application behavior through declarative configuration objects rather than imperative code. Hapi includes features for request lifecycle management, allowing developers to intercept and modify requests at various stages of processing. The framework supports plugin architecture, enabling modular application development and code reuse across projects. The framework provides built-in security features including input validation, output encoding, and CSRF protection. It offers authentication and authorization mechanisms through its plugin ecosystem, supporting various authentication strategies and access control patterns. Hapi includes monitoring and logging capabilities, providing insights into application performance and request handling. The framework supports both HTTP and HTTPS protocols and can be configured for various deployment scenarios.