Hidden networks are those networks who's SSID are Hidden. Who don't broadcast their SSID's.
For example you kept, MAX123 as you WiFi network name, so that's your SSID.
You can choose either to broadcast that name or keep it hidden.
When you choose not to broadcast your SSID, the network is still available and in many WiFi receivers, you can see those as Hidden Network.
Though your device is able to detect those networks but their SSID's are not broadcasted. Usually it helps for security concerns. When you don't want anyone else to discover your WiFi network.