#edit: Answers have been provided from previous threads. Thanks!

I've been doing a bit more digging into this important subject lately as it's something I've only ever skimmed but feel it deserves my proper attention at some point.

Something that's struck me as odd is how often I've heard the term Auschwitz in my life, yet before a few months ago I'd never heard of Belzec, Sobibor, Treblinka etc. From what I gather so far, the number of deaths wasn't as high as Auschiwtz as they came later during the advent of Operation Reinhardt. However, from the little I can find about these specific extermination camps (eg Belzec) it sounds to me like the sheer efficiency and brutality was another step above Auschwitz. The number I keep seeing is that only two people survived Belzec.

So basically, why has everyone heard of Auschwitz but no one has heard of Belzec? Is it because of this lack of info from survivors? Is it because of the length of time Auschwitz operated? Is it because of the total numbers? Is it a mix of these or none of the above?

Thanks in advance, and apologies if any of this is phrased in an uncouth manner for the subject.