SAMSUNG

Just go to Settings> "About phone". You can see the Samsung name and model number there.
 
 

I-PHONES

1. Open the "Settings" application
 
2. At the top, you will see your Apple ID / iCloud ID profile picture and your name. Press it.
 
3. Scroll down until you see your devices. The first device should be your iPhone; you will see the name and model of your device.