CSS Common Font Families

As web users use different operating systems with different fonts installed, the font specified for a web page may not be installed, so the page may not always look as it was intended.
The CSS font-family property allows you to specify multiple fonts. The browser will try to use the first font in the list. If it is not installed it will use the next and so on.
The following lists try to replace fonts with similar fonts on Windows, Apple and Unix, or on older versions of the operating systems which may still be in use and may not have the newer fonts.

Sans Serif
Simplier fonts used mainly for on-screen text

Arial, Helvetica, sans-serif
'Arial Black', Gadget, sans-serif
Tahoma, Geneva, Arial, sans-serif
'Trebuchet MS', Helvetica, Arial, sans-serif
Verdana, Geneva, sans-serif

Serif
Roman fonts used mainly for headlines and printed material.

Georgia, Utopia, Palatino, 'Palatino Linotype', serif
Times New Roman, Times, serif

Monospace
Fixed width fonts, used mainly for computer code.

'Courier New', Courier, monospace
Lucida Console, Monaco, 'Courier New', monospace

Done.