Macromedia's three graphics programs (Freehand, Fireworks, and Flash) use a system of repeating/repeatable objects called symbols. This page gives you a very basic rundown of how to use symbols and libraries. For more details about them, see our Flash help for symbols and libraries.
A symbol is an
object that you plan to use more than once in your image. For
instance, if you were making a picture of the night sky, you might
make an object called "star," which you could repeat throughout the
image. The advantage of using symbols is that if you decide you want
to change the look of them, you need merely alter the original symbol
and all its instances change.