Your router probably supports WPS and it’s likely enabled by default. Like UPnP, this is an insecure feature that makes your wireless network more vulnerable to attack. Wi-FI Protected Setup (WPS), was created to solve this problem but it had flaws which introduced vulnerabilities. So, the Wi-Fi alliance has presented a new way to connect to Wi-Fi connections with QR code scanning, now-a-days modern routers are now coming with small TFT screens which can show the QR code on it which can be then scanned through respective android and iOS devices. QR code scanning is efficient. Starting from Android 8.1.0 and later this feature has been removed from android operating system by Google.
