The hierarchy can use no more than three levels of font family, weight, and sizes. Use less fancy font families, Sans Serif font if possible. Make sure the font size is large enough to be legible
Serif versus Sans Serif
Serif means decorative edges on alphabets. And sans means without in French. As the names imply, Sans Serif fonts are plainer and more simplistic than Serif fonts in general. Let's take the most popular examples of default fonts in Microsoft Office. Times New Roman used in Office 2007 and before is a Serif font, whereas the newer Calibri is a Sans Serif font.
Serif means decorative edges on alphabets. And sans means without in French. As the names imply, Sans Serif fonts are plainer and more simplistic than Serif fonts in general. Let's take the most popular examples of default fonts in Microsoft Office. Times New Roman used in Office 2007 and before is a Serif font, whereas the newer Calibri is a Sans Serif font.