Why is the Jewish Holocaust called "THE Holocaust"? It isnt the only Holocaust! They happen all the time?!?

Calling it "The Holocaust" is not disrespectful to the genocide which has taken place, or is taking place, elsewhere now or in the past or future. It does not diminish the horror of genocide anywhere. However, there is no place where genocide comes even close to the numbers of Jews who were slaughtered in WW2. Referring to it as "The Holocaust" tells a person immediately that we are talking about the Jews during WW2 that's all.