Symbols are reusable objects that are stored in the Flash library. They are the building blocks you use to create animations. To put them in your animations you drag the symbol from the library onto the stage which creates an instance of the symbol.

Once you have created a symbol, you can use it over and over again. You can have several instances of the one symbol on the stage.

To create a symbol you have two choices:

When you have drawn something on the stage you can convert it to a symbol by selecting it, then choosing Modify > Convert to Symbol or by pressing F8.

You can draw a symbol from scratch in the symbol editor. Choose Insert > New Symbol

When you name your symbols, the name should only contain letters and/or numbers, no spaces or other special characters, and should start with a letter.

Once you have created a symbol it appears in the library.

You can create more copies of it on the stage simply by dragging out more instances of it from the library.

 

Editing Symbols

Create a new symbol.

Drag 2 or more instances of the symbol from the library onto the stage.
Now go to the library and double click on the name of the symbol.
The stage looks a little different and if you look at the top of the window you can see that you are no longer in Scene 1 with the main timeline. You are in the symbol editor.
Edit your symbol in any way you like in the symbol editor.
Now return to the main timeline by clicking on Scene 1 at the top of the window.
You will see that every instance of the symbol has been modified.
 

It is also possible to do some limited editing of a single instance of a symbol.

You can use the free transform tool to change its shape or size etc.

You can also use the properties window to alter the properties of an instance such as colour effect, tint or transparency of a single instance of an object on the stage.

 This video may help you if you are still unsure of how to create and use symbols.

Create a symbol of your own choice using the drawing tools and place 6 different instances of it on the stage.

This Flash animation shows how symbols can be used from the library. Animator vs Animation