Node.js is an open-source server environment. Node.js allows you to run JavaScript on the server.

What is Node.js?

• Node.js is an open-source server environment
• Node.js is free
• Node.js runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
• Node.js uses JavaScript on the server

Why Node.js?

A common task for a web server can be to open a file on the server and return the content to the client.

Here is how PHP or ASP handles a file request:

1. Sends the task to the computer’s file system.
2. Waits while the file system opens and reads the file.
3. Returns the content to the client.
4. Ready to handle the next request.

Here is how Node.js handles a file request:

1. Sends the task to the computer’s file system.
2. Ready to handle the next request.
3. When the file system has opened and reads the file, the server returns the content to the client.

Node.js eliminates the waiting and simply continues with the next request.

Node.js runs single-threaded, non-blocking, asynchronous programming, which is very memory efficient.

What Can Node.js Do?

• Node.js can generate the dynamic page content
• Node.js can create, open, read, write, delete, and close files on the server
• Node.js can collect form data
• Node.js can add, delete, and modify data in your database

What is a Node.js File?

• Node.js files contain tasks that will be executed on certain events
• A typical event is someone trying to access a port on the server
• Node.js files must be initiated on the server before having any effect
• Node.js files have the extension “.js”

Node.js, commonly known as Node, is a free and open-source server-side JavaScript runtime environment that runs on Chrome’s V8 JavaScript engine.

Node.js is a lightweight and scalable platform that allows developers to build high-performance applications and web services. Since its release in 2009, Node.js has gained a massive following among developers and businesses due to its speed, simplicity, and versatility.

One of the key benefits of Node.js is its ability to handle a large number of concurrent connections without blocking any I/O operations.

This is made possible by its event-driven, non-blocking I/O model, which makes it ideal for building real-time web applications, chat applications, and online games that require constant interaction with the server.