A family of Microsoft word processing software products for creating web, email, and print documents.
If you look in the Font dialog box, or in any drop down where fonts are listed, you'll see the options I mentioned earlier: "Body" and "Heading." If you apply either "Body" or "Heading" to text, the actual displayed font will be determined by the theme fonts.
You can experiment with this yourself.
The following screen shot is from a document of mine:
As you can tell from the Font dialog box, the font is set to "Body." In the document, the actual font becomes Times New Roman because of my current theme settings. If I choose a different theme, I will get a different font.