What is Node.js and How Does it Work?

The Architecture of Node.js

Created by Ryan Dahl in 2009, Node.js represents a seismic shift in server-side paradigms. It is a JavaScript runtime environment forged by wrapping Google Chrome's highly optimized V8 compiler inside a sophisticated C++ operational shell.

The Non-Blocking I/O Paradigm

Traditional servers (like Apache) operate using a Thread-Per-Request model, creating heavy memory overhead and thread-context-switching delays for thousands of users. Node.js executes all JavaScript strictly on a Single Thread.

When the single thread encounters a slow Database query, it does not wait. It delegates the I/O operation entirely to the underlying OS Kernel via libuv, registers a callback function, and instantly moves to the next incoming HTTP request. This Event-Driven, Non-Blocking architecture allows Node.js to comfortably handle thousands of concurrent I/O operations with a minuscule RAM footprint.