Node.js — Run JavaScript Everywhere

# Node.js Documentation > Node.js is an open-source, cross-platform JavaScript runtime environment that executes JavaScript code outside a web browser. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient for building scalable network applications. Below are the sections of the API documentation. Look out especially towards the links that point towards guidance/introduction to the structure of this documentation. ## API Documentations - [Debugger](https://nodejs.org/docs/latest/api/debugger.md): Node.js includes a command-line debugging utility. The Node.js debugger client is not a full-featured debugger, but simple stepping and inspection are possible. - [Deprecated APIs](https://nodejs.org/docs/latest/api/deprecations.md): Node.js APIs might be deprecated for any of the following reasons: - [UDP/datagram sockets](https://nodejs.org/docs/latest/api/dgram.md): The `node:dgram` module provides an implementation of UDP datagram sockets. - [Diagnostics Channel](https://nodejs.org/docs/latest/api/diagnostics_channel.md): The `node:diagnostics_channel` module provides an API to create named channels to report arbitrary message data for diagnostics purposes. - [DNS](https://nodejs.org/docs/latest/api/dns.md): The `node:dns` module enables name resolution. For example, use it to look up IP addresses of host names. - [About this documentation](https://nodejs.org/docs/latest/api/documentation.md): Welcome to the official API reference documentation for Node.js! - [Domain](https://nodejs.org/docs/latest/api/domain.md): **This module is pending deprecation.** Once a replacement API has been finalized, this module will be fully deprecated. Most developers should **not** have cause to use this module. Users who absolutely must have the functionality that domains provide may rely on it for the time being but should expect to have to migrate to a different solution in the future. - [C++ embedder API](https://nodejs.org/docs/latest/api/emb