You can also view previously answered questions in the HSW Question Archive . I have always wondered what AWG means and how wire gauges work in general.
Bullets come in variety of different calibers .
The caliber indicates the diameter of the bullet. For example, you have probably heard of a .22 caliber rifle . In all of these cases the caliber number indicates the diameter of the bullet in inches. So a .25 caliber bullet is a quarter of an inch in diameter. This page has a lot of information on bullet calibers.