We have that on our house and around here it is called lap and gap. I have replaced some rotted courses and had to go to a lumberyard to get what I wanted. I have examined this type of siding in detail.
cedar lap and gap siding
Ship lap siding is installed without gaps, but there will be grooves. Lap and gap has a much longer lap on one end resulting in a distinctive wide horizontal gap. Some (lap and gap) siding can be installed with the rough side out to give lap and gap, but if installed with the smooth side out the result is no gap outside giving the effect of ship lap. However, there will be an internal gap. I would think that ship lap would have only a very narrow gap or no gap, just a groove.
Look at the design of the planks in the link.