On the wikipedia page: http://de.wikipedia.org/wiki/Nebelhorn It has on the first sentence that; Das Nebelhorn ist ein Signalhorn zur Erzeugung von Schallsignalen oder Nebelsignalen in der Schifffahrt. On the English article version for this the first sentence states; A foghorn is a fog signal that uses sound to warn vehicles of navigational hazards or boats of the presence of other vessels in foggy conditions. My attempt at a translation of the German part: The fog horn is a signal horn for generating sound signals or fog signals in shipping. I know that these wiki articles are not meant to be direct translations of one another, but I am confused as to the Das in this sentence. I have seen in some grammar lessons that; Der, die and das are the same as "the" in English - the DEFINITE ARTICLE. and that; The INDEFINITE ARTICLE ("a" or "an" in English) is ein or eine in German. I also know that at times Das can be omitted in some translations to just state the noun, such as Das Boot (boat) But I wonder why they didn't write this as Eine Nebelhorn instead of Das Nebelhorn. Wouldn't this sound more appropriate and natural in German?