The font CSS property is either a shorthand property for setting font-style, font-variant, font-weight, font-size, line-height and font-family, or a way to set the element’s font to a system font, using specific keywords.
As with any shorthand CSS properties, the values which are not set in it are set to their individual initial values, eventually overriding values previously set using non-shorthand properties.

<!DOCTYPE html>
            /* Set the font size to 12px and the line height to 14px. 
             * Set the font family to sans-serif */
            p {
                font: 12px / 14px sans-serif
            /* Set the font size to 80% of the parent element or 
             * default value (if no parent element present)
             and set the font family to sans-serif */
            p {
                font: 80% sans-serif
            /* Set the font weight to bold, the font-style to italic, 
             * the font size to large,and the font family to serif. */
            p {
                font: bold italic large serif
            /* Use the same font as the status bar of the window */
            p {
                font: status-bar
    		You can easily change the formatting of selected text in 
			the document text by choosing a look for the selected 
			text from the Quick Styles gallery on the Home tab. 
			You can also format text directly by using the other 
			controls on the Home tab. Most controls offer a choice 
			of using the look from the current theme or using a 
			format that you specify directly.