The death camps, killed six million or so jews, out of almost 10 million killed..
in addition, as german forces moved eastward, they didn't much distinguish between civilians or military targets. the russians, had, like germany a stong central goverment, and good records, so we know more about the numbers. much of poland was rural, and church (baptismal and death) records were more accurate than government reords.. so the tally of the dead in these countries is harder to know.

jewish organizations have made a point about keeping holocast details about jews in the news, so 'everyone' knows about them. but the devistation in europe was pretty wide spread, and got worse and worse as one moved east.

While poland did have large industrial cities (Warsaw and Gdanzt and other) it also had a large rural population. small town and villages, sometimes escaped, other times, were killed... the entire village slaughtered, and building leveled, the whole place whiped of the map.