Final answer:
The letters 'QR' in QR code stand for Quick Response, denoting a two-dimensional barcode designed for fast readability and large storage capacity.
Step-by-step explanation:
The letters in the term QR code stand for Quick Response. QR codes are two-dimensional barcodes that can store a wide variety of information and are designed to be scanned using a smartphone camera or a dedicated QR code reader, providing a rapid way to access data such as URLs, contact information, or text. When QR codes are scanned, the scanning device typically interprets the information encoded within the pattern of black squares and then takes action, such as opening a website or saving data to a phone.