QR code, short for Quick Response code, is a two-dimensional barcode that was first developed in 1994 by a Japanese company called Denso Wave, a subsidiary of Toyota. QR codes are designed to store information, such as text, URLs, contact information, or other data, in a pattern of black squares arranged on a white background. They can be scanned and read using a smartphone or a QR code reader, allowing users to quickly access the encoded information.

1. Data Capacity: QR codes can store a significant amount of data compared to traditional one-dimensional barcodes. Their capacity ranges from a few dozen characters to several thousand characters, depending on the type and size of the QR code.

2. Encoding: QR codes encode data using patterns of black squares (modules) arranged in a square grid. The arrangement of these squares represents the encoded information.

3. Error Correction: QR codes include error correction capabilities, allowing them to remain functional even if the code is partially damaged or obscured. Error correction ensures that the encoded data can still be accurately retrieved.

4. Versatility: QR codes can store various types of data, including text, URLs, numeric data, and binary data. This versatility makes them suitable for a wide range of applications.

5. Scanning: QR codes can be scanned using the camera of a smartphone or a QR code reader device. Many modern smartphones have built-in QR code scanning functionality in their camera apps.

1. Mobile Payments: QR codes are used in mobile payment systems. Payment apps generate QR codes containing payment information. The customer scans the code to make a payment.

2. Marketing and Advertising: Marketers use QR codes in advertisements, posters, and product packaging to provide additional information or links to websites, videos, or promotional offers.

3. Ticketing and Boarding Passes: QR codes are widely used in electronic tickets for flights, concerts, movies, and public transportation. Scanning the code grants access.

4. Contactless Menus: Especially in the post-pandemic era, restaurants use QR codes to provide digital menus accessible via smartphones, reducing physical contact with printed menus.

5. Information Sharing: QR codes on business cards or promotional materials allow users to quickly save contact information, website links, or other details to their smartphones.

6. Inventory and Tracking: QR codes are used in inventory management to track products and manage stock levels efficiently.

7. Education: In educational materials, QR codes can link to online resources, videos, or interactive content, providing additional learning materials to students.

QR codes have become ubiquitous in various industries due to their convenience and ease of use, enabling efficient information sharing and interaction between users and digital content.