How Node.js works

In this section, you’ll learn how Node.js operates internally and be introduced to the reactor pattern, which is central to Node.js’ asynchronous nature. We’ll cover key concepts like the single-threaded architecture and non-blocking I/O, and show how these elements form the basis of the Node.js platform. Understanding how Node.js works will be crucial for mastering the runtime and writing clean, efficient code.

While we commonly describe Node.js as “single-threaded” due to its ability to handle asynchronous tasks concurrently on a single thread, this doesn’t mean it can’t leverage background threads for certain operations. Node.js uses a single thread for the event loop, but when needed, it can execute CPU-intensive tasks on separate threads, allowing for more efficient handling of complex operations. In Chapter 11, Advanced Recipes, we’ll explore how to use worker threads to perform such CPU-heavy...