The acronym 'QR' stands for 'Quick Response', referring to a type of matrix barcode that can be scanned by smartphones and other devices. QR codes store data, such as URLs, contact information, or text, and can be quickly accessed by users to retrieve pertinent information. They are widely used in marketing, allowing businesses to effectively connect with consumers by enabling easy access to online content, promotions, or additional product details, streamlining customer interaction.