Payment and Banking  
https://make-qr.github.io/ 
One of the most popular uses of QR codes is in cashless payments. From coffee shops to supermarkets, customers can simply scan a QR code to pay instantly through mobile apps. This not only saves time but also promotes safe, contactless transactions. 
2. Advertising and Marketing 
QR codes are now a common feature in advertisements, posters, product packaging, and business cards. By scanning the code, users can quickly access websites, promotional videos, discount vouchers, or social media pages, making marketing more interactive and measurable.