iPhone 15 supports USB-C/Ethernet adapters for connecting wired Internet.
In this case, the Internet speed may be faster than Wi-Fi. Some users experience download speeds of up to 870 Mbps over Ethernet.
When your smartphone is connected to wired Internet, the iOS device displays Ethernet. This menu displays the device’s IP address and network settings.
This feature is not new for iPhones. Models with Lightning also use Ethernet, but it’s nice that Apple kept it, despite changing the connector and increasing the speed.
Source: Iphones RU

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