QR codes offer a versatile method for storing and sharing information, and Node.js provides efficient tools for reading and writing these codes. The text explains how to use Node.js with three popular libraries: qrcode for generating QR codes, and qrcode-reader and jimp for reading them. It outlines the installation and usage of these libraries, demonstrating how to create QR code images in various formats, such as PNG and SVG, and how to decode them from image files. Additionally, an example is provided of how a Node.js backend can authenticate users by generating and validating a JWT token using a secret derived from a QR code. This process involves setting up a server with Express, implementing routes for user login, and using JSON Web Tokens for secure client-server communication. The guide also emphasizes the importance of monitoring and maintaining server performance with tools like LogRocket, which assists in identifying and resolving issues by capturing user sessions and performance metrics.