QR or (Quick Response) are a two dimensional bar-code system.
Mobile QR codes is when a consumer uses a smartphone to scan these codes
to reveal their information.
Today they are used in many ways, from inventory tracking, to shipping and logistics,
to online ticketing, also to link to promotional videos on YouTube or set reminders
for upcoming shows. Other applications include putting Google Maps directions on
a business card, to linking to a web page, or even sending a text/email to the company helpline.
Here is an infographic with Statistics showing the amazing growth of QR Code usage.