what's the layer application in digital photography

I noticed the “layer” jargon in my camera’s software as well as in some expert’s posts.
I do not know the layer’s function and its applications in digital photography. Is there any one to help me?
Vafa

Vafa,
You would need to be a little more specific. Layering usually refers to a type of image-manipulation system used widely in profesional image editing. Check out this link to learn more.

Layers

Vafa,
As a fellow newcomer, my understanding of layers might be helpful. With photo editing programs like Photoshop Elements, you can create a composite picture by using layers. I think of the layers as being like stacking a series of transparencies on an overhead projector. In the editing programs the layers give you control of the individual elements in the picture -- you can make corrections in the background layer without changing the foreground layers, etc.

Jim