Connecting raspberry to phone wifi similar to a product

Question

I'd like to connect my Raspberry to wifi just like products (cameras) where you enter a MAC ID or scan a QR code to your phone and then it is connected to your phone and if you want to further connect it to internet, in the product's app they ask for the internet SSID and password.

My question is, how do they do this? It seems initially, a wifi connection gets established between phone and the device and then when internet SSID and password entered, the app provides that information to the device and the device configures its wifi to connect to the internet.

Any explanation that clarifies the process and offers some details on how to implement this would be appreciated.

Answer 1

There is a way called wifi ad-hoc which enables wifi to be connected directly. There is a bunch of guides to do implement this.