The wattage of a USB-C charger determines how quickly it can charge your device. A higher wattage charger can charge your device faster, but only up to the device's maximum charging capabilities. Plugging an iPhone into a 240-watt charger won't instantly charge the iPhone; it will only pull about 20 watts, the maximum the phone can charge.
This stand can charge an iPhone, Apple Watch, and AirPods wirelessly, all at the same time. It connects to the stand via USB-C and thus can be used as an Apple Watch charger with any USB-C.