Is HTML is used only for webpage

Question

Answer if possible

Answer 1

Yes, html is only used to make a skeleton structure of a webpage.

Answer 2

No , HTML you can use , for example, when you create app , in QT creator u can use HTML , CSS to write text on buttons or in menu with styles , change color and etc.
I heard that you can use HTML in hacking ( and how it is right I dont know))))