A QR code (quick response code) is a type of matrix barcode (or two-dimensional barcode).invented in 1994 by the Japanese automotive company Denso Wave. A barcode is a machine-readable optical label that can contain information about the item to which it is attached. In practice, QR codes often contain data for a locator, identifier, or tracker that points to a website or application. A QR code uses four standardized encoding modes (numeric, alphanumeric,binary, and kanji) to store data efficiently; extensions may also be used. Get more information at. Wikipedia

There is no limit to scan qr code, you can scan qr code as many time as you want.

QR codes are valid for as long as you want and will never expire. The only instance where the code might ‘expire’ is when the destination URL is changed or deleted.

You can design a QR code and put it on your website, flyer, business card, product packaging, menu, or even on a billboard. Use a QR code to send customers to a particular product page, to your social media account, to connect to WiFi and so much more.

Most smartphones have a built-in QR scanners, which are sometimes built in the camera. A QR scanner is simply a way to scan QR codes.Some tablets, such as the Apple iPad, have QR readers built into their cameras. Some older devices may require a particular app to read QR codes, these apps are available on the Apple App Store and Google Play.

You can make as many QR codes as you want; your QR code will never expire and will be valid for a lifetime.

A vcard QR code is a type of QR code that people place on their business cards, so when people scan they have in one click all your information saved to their phone.

Static QR Codes encode the final data which is displayed after a scan, for example, a product info qr code.