Question

How QR codes work and Why they are required ?

Answer 1

QR Codes are the abbreviated version of an information such as product or service

For example, you are on the subway and there is promoted a discount for tickets to a concert. You scan the QR code and you will be directed to the organizator`s page, where you can buy the ticket you want

They are pretty useful, but sometimes they generate errors

Answer 2

QR (Quick Response) code is the trademark name for the two dimensional barcode system. It was originally invented in 1994 by Denso Wave, a Toyota subsidiary, as a way to track vehicles as they were assembled, and to scan components at high speeds. QR codes have long since expanded their usefulness beyond the automotive industry. They're used today in everything from inventory tracking, to shipping and logistics, to online ticketing (Fandango is a big fan). Bands put them on fliers to link to their videos on YouTube or set reminders for upcoming shows. Businesses use it to put Google Maps directions on a business card, automatically load a web page, or send a text/email to the company helpline.
For more information you can visit this gizmodo.com/5969312/how-qr-codes-work-and-why-they-suck-so-hard

Thanks :-)