The device name on Galaxy S7 is mainly used when you try to share files via Bluetooth or connect it to Smart TV or computer. To change device name on Galaxy S7 and Galaxy S7 (Edge), do as follows:
1. Open the Settings app (Open it from the notification panel or from the app drawer)
2. Scroll all the way down to the System settings and touch the About Device option (or Device Information)
3. Tap to open the Device Name option (It's usually under the Software update, Status, and Legal information options)
4. Type a new name as your Device Name and hit the OK button
5. From now one, this name will be displayed when you try to connect to a Bluetooth device, share files using Wi-Fi Direct and more.