What does node.js do

Node.js is a JavaScript running environment based on the Chrome V8 engine, which is used to build high-performance and extensible network applications. Node.js is mainly used for server development, but it can also be used to develop command line tools and desktop applications.

The following are the main functions and uses of Node.js:

1. Server side development: Node.js provides a lightweight and efficient way to build server side applications. It uses an event driven, non blocking I/O model, which enables it to handle a large number of concurrent requests and has excellent performance.
2. Network application development: With Node.js, you can develop various types of network applications, such as Web applications, real-time chat applications, blog platforms, etc. Its powerful event processing mechanism and rich library ecosystem make the development of these applications more simple and efficient.
3. API development: Node.js can be used as the back end for building and providing RESTful APIs. It provides many libraries and frameworks (such as Express and Koa), making it possible to quickly develop and manage APIs.
4. Command line tool development: Node.js can be used to develop command line tools and scripts to facilitate file operations, data processing, automated tasks, etc.
5. Real time application development: Because Node.js has the characteristics of event driven and non blocking I/O, it is very suitable for developing real-time applications, such as instant messaging, multiplayer games, etc.
6. Desktop application development: With the help of a framework (such as Electron), you can use Node.js to develop cross platform desktop applications, such as editors, chat clients, etc.

In a word, Node.js provides a powerful JavaScript running environment, enabling developers to use JavaScript to build high-performance and extensible applications on the server side, and has a wide range of applications in network applications, API development, command line tools and real-time applications.