Due to how TV, monitor, laptop, phone and loudspeaker manufacturers specify things, most europeans operate quite freely with inches. 15" laptops are still marketed as 15" laptops here, not 38cm laptops. We just got used to it.
Just dont start speaking to europeans about fluid ounces, bushels of wheat and other such weird things🙃
I think you mean social democracy. Democratic socialism is a form of socialism.