Every theme assigns one font to and one to

This question is related to the themes of Microsoft office and in that every office theme have two fonts to define, and every theme assigns one font to headings and one font to body text.
When we are using Microsoft word, we use the different font for heading and different for text but sometimes we use the same font but the theme is changed to distinguish heading from the other text.

White dwarf is very hot, but also very small and that is why it may appear dim.