Nazisploitation is a word usually used to describe the number of (mostly Italian) exploitation films made during the '70s that revolved around the sordidly sexual or gruesome goings-on at Nazi concentration camps/stalags/extermination camps; and in my own estimation, that is the true definition of the term, and there are only around 30 films which qualify as such.

However, I personally also believe that Nazisploitation has even earlier roots, and has also continued to evolve since it's heyday. I submit that there are four major schools of the subgenre:

1) the aforementioned '70s shock exploitation pictures,
(Ilsa, Love Camp 7, Gestapo's Last Orgy)
2) War-era Allied propaganda pieces/Post-War mad Nazi scientist pictures,
(Enemy of Women, Strange Holiday, She Demons, The Frozen…