WWII/Holocaust...Separate?

When the textbook separates WWII and the Holocaust, it makes the Holocaust seem like a whole separate piece of history. To me, it does not make sense to separate the Holocaust with WWII. If I had organized the text book, I would have put the Holocaust together with WWII so they are taught at the same time. Although the Holocaust was catastrophic, I would not put it on its own pedestal because it did not occur in a totally different time period. Yes, the Holocaust was one of the most devastating events in world history, but I would teach it along with WWII.