What components or principles form the basis of the framework you use?

Many popular Node.js frameworks, such as Express.js, are based on the following principles and components:

• Middleware — a chain of functions that handle requests and responses, allowing flexible extension of functionality.
• Asynchronous and event-driven architecture — using non-blocking I/O and Node.js's event loop for high performance.
• Routing — defining paths and handlers for various HTTP requests.
• Inversion of Control (IoC) and Dependency Injection — for managing dependencies and simplifying testing (in some frameworks).

For example, Express.js is built around the concepts of middleware and routing, enabling the creation of request processing chains with the ability to add custom logic.