Node.js is an open-source and cross-platform JavaScript runtime environment. It is built on top of the V8 engine (which is also used by Google Chrome) and provides an event-driven, non-blocking I/O model for building scalable and efficient web applications.

Node.js architecture is based on two main concepts: callbacks and event loop. The event loop is a mechanism that enables Node.js to handle I/O operations in a non-blocking way, which means that while a certain task is being executed, other tasks can continue running seamlessly without waiting for it to finish. This allows Node.js to be highly efficient and scalable.

Callbacks are functions that are passed as arguments to other functions and are called when an operation is completed. In Node.js, callbacks are commonly used to handle asynchronous operations, such as reading or writing files, sending requests to databases, or making HTTP requests.

In addition, Node.js also provides a number of built-in modules that simplify the development process. These modules include the http, url, querystring, and fs modules, which make it easy to perform tasks such as creating a web server or reading and writing files.

Overall, Node.js architecture is designed to enable developers to write high-performance and scalable web applications using a simple and intuitive programming language, JavaScript. By using Node.js, developers can build fast and efficient web applications that can handle large amounts of traffic and scale to meet the needs of their users.

Node.js architecture refers to the way Node.js works under the hood, including its various components and how they interact with each other. Understanding the architecture of Node.js is essential for developers to build scalable and efficient applications.

Node.js has a unique architecture called event-driven, non-blocking I/O model. The core of Node.js is built on the V8 JavaScript engine, which provides high performance and executes JavaScript code efficiently. The architecture of Node.js is based on modules, which are reusable pieces of code. These modules can be combined to create a complete functionality of an application.

Node.js includes several built-in core modules that provide essential functionality like file system access, networking, and HTTP/HTTPS handling. For additional features, Node.js has a vast ecosystem of third-party modules available on npm repository.

The event-driven, non-blocking approach of Node.js allows handling the significant number of concurrent connections without being blocked. Event-driven architecture works through an event loop, which continuously checks for incoming events and dispatches them to the appropriate handlers. This approach enables Node.js to handle a large number of clients simultaneously.

The non-blocking I/O model allows Node.js to scale efficiently by using a single thread to handle many client requests. This model facilitates better processing on a multi-core system with the help of clusters. Node.js clusters distribute the load across multiple CPUs, enabling an application to process more requests in parallel.

In summary, Node.js architecture consists of modules, event-driven, and non-blocking I/O model, and clusters, which altogether provide a scalable and efficient foundation for developing web applications.