What this CSS code means (font-size division)?

Question

Sorry everyone, I really can\'t find any better title for my question.

I have encountered with this code

font: 9pt/18px Tahoma;

Do

Answer 1

/* The shorthand */
font: 9pt/18px Tahoma;

/* The expanded version of the above style */
font-size:9pt;
line-height:18px;
font-family:Tahoma;