Definition of PCB layers

Community PCB Design
1

First time circuit creation, first time eagle free version user, first time BatchPCB user. Now that you know my credentials…

What is the definition of 2 layer? Is it bottom copper and top silk screen? (a single sided board). Or is it bottom copper AND top copper traces and top silkscreen? BatchPCB lists the prices for 2 layers, and in the Eagle autoroute I have the option of top and bottom (layers 1 and 16).

Routing would be a lot easier on a compact board if I can put some traces on the top, and then have the silk screen there to. IF this is what 2 layer is, is there some type of insulating film between the top traces and the silk screen images of the components?

2

Two layer would be top copper and bottom copper layers (sometimes called component side and solder side), and optional things like silk screen, solder mask and paste mask. Think of it as two electrical layers. The other stuff is non-electrical.

3

Thank you.