What is the purpose of a pure virtual destructor?

Question

I had a look at this but still don't understand the need to have them.

https://www.studytonight.com/cpp/virtual-destructors.php

Answer 1

https://stackoverflow.com/questions/1219607/why-do-we-need-a-pure-virtual-destructor-in-c

Answer 2

Pure vertual functions are used to declare the abstract classes to ensure that the abstract class will no be used and in any call of the function compiler will skip this function and search for its overload in the childrens