The HTML (hypertext markup language) appears whenever you can format text within D2L.  It does not appear in files you have simply uploaded to D2L, such as a Microsoft Word file.  Word processing programs also use HTML to format text.  Some people worry that HTML means they will need some knowledge of coding to use it, but that is not true.  The HTML editor in D2L is like most HTML editors in word processing programs, meaning that clicking a button will change the font.