Enabling the hotspot feature on the smartphone allows the device to create a Wi-Fi network that other devices can connect to for Internet access. This is especially useful in areas where no other Wi-Fi connection is available. Tethering typically refers to sharing a device's internet connection with another device via USB, Bluetooth, or Wi-Fi, but the term 'hotspot' more specifically conveys creating a Wi-Fi network for multiple devices to join. Airplane mode and data roaming are not relevant to creating a local Wi-Fi network for other devices.