I would think that the standard Cruise Control for Porsche is the same as we have in North America, very easy to use and controlled by a stalk on the steering column. One push of a button at the end of the stock to turn it on and push forward to enable and the speed you are currently traveling is set and maintained unless you touch the brakes or depress the clutch on a MT car or pull back on the stalk. Push the lever up to increase speed by 1km/hr, press down the stalk to decrease the speed by 1km/hour, finally push the button once again to turn off cruise control.
Sorry if this is not 100% right as I am still waiting for my 718 to arrive, currently without a car since last summer.
Still amazes me that standard cruise control is an extra cost option over there as it comes standard here.