In one sense, each such quote is a blurb*. It’s not clear to me whether “Klappentext” refers to everything on the back of a book, but if it does then blurbs form all or part of that.
In another sense, we might use “blurb” to mean everything on the back of a book. I’m not completely sure which is correct, but when in the plural for one book, it’s definitely being used as a synonym for “quote” with a little added context.
* I’m not even sure whether “blurb” refers to only a quote or to the quote and its following attribution. Dictionaries are not clear on this.
!["A book that will shock the conscience of a nation" [Too Much Coffee Man]](https://lemmus.org/pictrs/image/8f8238f4-d620-4e38-8d14-8747e0ed3915.webp){kind=link}
In one sense, each such quote is a blurb*. It’s not clear to me whether “Klappentext” refers to everything on the back of a book, but if it does then blurbs form all or part of that.
In another sense, we might use “blurb” to mean everything on the back of a book. I’m not completely sure which is correct, but when in the plural for one book, it’s definitely being used as a synonym for “quote” with a little added context.
* I’m not even sure whether “blurb” refers to only a quote or to the quote and its following attribution. Dictionaries are not clear on this.