What is layers?
Layers are a transparent sheets placed over each other. Separated from the existing object. At the same time make orderly object over each other.
Layers also help you to work different animations in each layer. Each animation is not related to the other.
Where is the layers?
At the first when you create new document in flash there will be one layer named layer 1 in almost the upper left hand on the flash screen.
How you can add a new layer?
How you can rename the layer?
Double-click on the layer name, rename it.
How you can delete the layer?
Notes: if you have only one layer you can delete it.