Win 10 is not included, as no hard disk is installed. RAM (DDR4-2400, SO-DIMM 260 pin) and SSD (e.g. https://www.digitec.ch/de/s1/product/samsung-pm981a-bulk-512gb-m2-2280-ssd-12253923) must be purchased, as well as a Win 10 licence. But there are also complete systems: Intel NUC 8 Mainstream-G (Intel Core i7-8565U, 8GB, 256GB, SSD)

No software, no RAM, no hard drive. The NUC consists virtually only of the housing, mainboard and processor.
Nevertheless, it's a super device. I've had a total of 7 of these small parts in the office for a year and am highly satisfied. Recommendation: 16 GB RAM and a 1TB NvME SSD (e.g. 970 evo+) and the little thing runs like crazy. Super reliable, super update supply via Intel.