What Does A Wart Look Like When It Dies> Die-hard Pimples Or Warts?

Die-hard pimples or warts? - what does a wart look like when it dies>

I have buttons on top of the shoulders in the summer when the sweat is not really a problem, a little cream of wheat and I feel fine.
But perhaps had in the last 2 years I have, what appears to be a big corn on each shoulder, which never disappears.
It looks like a grain of it is a white head shape and be able to pop, but never does. And they stay around all year.
Someone said recently that a wart can be.
Is that true?
What is it?