Sauerkraut, directly translated: sour cabbage, is finely cut cabbage that has been fermented by various lactic acid bacteria. It has a long shelf life and a distinctive sour flavor, both of which result from the lactic acid that forms when the bacteria ferment the sugars in the cabbage. (Wikipedia.)
In short, it is kimchi without the spicy red sauce. It is more nutritious than normal cabbage because the fermentation process increases the bioavailability of nutrients, whatever that means.
I had it with bratwurst and bread, at an outdoor restaurant near Dom/Romer square. The wurst was fabulous, it was totally, absolutely yum. The sauerkraut, I found to be a bit bland in taste, so I had to resort to the assortment of Heinz sauces to spice it up a little.
