The default typeface for all HTML elements is TImes New Roman.

　　exmaple as use of font typeface:  font-family: "Courier New"; 

Two different typefaces of types as:

　　1.Serif - traditionally used in print designs, as they have been considered easier to read in long paragraphs of text. Like Times New Roman and Georgia.

　　2.sans serif - can look better and be easier to read. Like Arial and Helvetica.

When the stylesheer specifies a font not installed on user‘s computer, the pre-installed fonts can be used as fallback fonts for users.

　　exmaple as fallback fonts typeface as: font-family:Garamond, Times, serif;

Google offers Google Fonts, a firectory of thousands of open-source fonts that are free to use by anyone.To use a Google Font,you can use a <link>element in html file.

　　For exmaple, we use Raleway typeface:

　　<link href=http://www.mamicode.com/"https://fonts.googleapis.com/css?family=Raleway" type="text/css" rel="stylesheet" >

　　or use Playfair Display typeface:

　　<link href=http://www.mamicode.com/"https://fonts.googleapis.com/css?family=Playfair+Display" type="text/css" rel="stylesheet" >

To change the size of text on your web page, yoiu can use the font-size property.

　　for exmaple, we use that:

　　font-size :18px

　　font-size: 1.3em

　　font-size: 150%

【codecademy summary】html+css font