QR codes (Quick Response codes) are a type of two-dimensional barcode that store information in a square grid pattern. They were developed by Denso Wave, a subsidiary of Toyota, in 1994. Here are details about QR codes, their families, and their features:

1. QR Code Families:
– QR Code Model 1: The first version of QR codes, capable of storing up to 7,089 numeric characters or 4,296 alphanumeric characters.
– QR Code Model 2: An enhanced version with increased storage capacity, capable of storing up to 16,953 numeric characters or 7,089 alphanumeric characters.
– Micro QR Code: A smaller version of the QR code designed for applications where space is limited. It can store up to 35 numeric characters or 21 alphanumeric characters.
– iQR Code: A high-capacity QR code that can store significantly more data compared to traditional QR codes. It supports multiple encoding modes and error correction levels.

2. Features of QR Codes:
– High Data Capacity: QR codes can store much data compared to traditional linear barcodes. They can hold various data types, including text, URLs, contact information, Wi-Fi network details, and more.
– Error Correction: QR codes incorporate error correction techniques, allowing them to remain readable even if the code is partially damaged or obscured. Error correction levels range from 7% to 30%, providing a balance between data capacity and error resilience.
– Fast Scanning: QR codes can be quickly scanned and decoded using smartphones, tablets, or dedicated barcode scanners. This enables fast access to information encoded within the QR code.
– Versatility: QR codes can be printed on various surfaces, such as product packaging, labels, posters, and advertisements. They can also be displayed on digital screens for scanning with mobile devices.
– Customization: QR codes can be customized with different colors, designs, and logos while still maintaining their scannability. This allows businesses to incorporate branding elements into QR codes.
– Mobile Interaction: QR codes are commonly used for mobile interactions, such as accessing website URLs, making payments, downloading apps, adding contacts, and connecting to Wi-Fi networks.
– Offline-to-Online Bridge: QR codes act as a bridge between offline and online experiences. They enable users to quickly access additional information, promotions, or interactive content related to physical products or locations.

Overall, QR codes offer a versatile and efficient way to encode and decode information. Their high data capacity, error correction, fast scanning, and mobile interaction capabilities make them valuable tools for marketing, advertising, product information, and various other applications.