Layers Continued

Here is a picture I took of my layer’s pallet.  There are different kinds of layers and they all look a little different.  Let’s start at the bottom.  Background Layer:
When you start a new project you will see only one layer in the layers palette, named Background.  There is a little lock to the right of this layer indicating that it is locked.  The background layer is always locked by default when you open a  photo or a new document,but there are times when unlocking the background layer is necessary . To do this double-click the layer on the layers palette.  The new layer dialog box will open and you can either give the layer a new name or you can just hit OK.
Element Layer
This kind of layer shows any elements that you might have place on your page. It also shows where on your page it is place.  The Layer has a checkerboard pattern indicating that except for the element the page is transparent and contains no pixels.  The name to the right will be what ever the designer named the element you can double click on any name and re-name it.
Shape Layer
When you add a shape or add text a new layer is automatically created.  Layers created with these tools are vector layers which means basically that it does not use pixels  and so it can be resized without losing any quality.  My shape layer here has a gray area with just the shape showing in the bottom right. If I simplify the shape or text it become like the element layer with a transparent background.
Text layer
The Text Layer always has a big T in it.  The name to the right of the layer will be what ever you typed.  You can simplify this layer like a shape layer but then you can not edit your text.
Adjustment Layer with mask
The adjustment layer applies some sort of modification to the layer directly beneath it.  There are eight adjustment layer types:  Levels, Brightness/Contrast, Hue/Saturation, Gradient map, Photo filter, Invert Threshold, and Posturize.  You can also add these from the command bar directly to an image but if you create an adjustment layer you can do more with it. 
1.  The effect remains editable… you can change the settings.
2.  It is not-destructive which means that the command doesn’t’ touch the pixels in the layer beneath it you can always go back to your original image
3.  It comes with a  layer mask which lets you apply the effects selectively to the parts you want.

I know this is a bit confusing so I will show you how to use an adjustment layer in this post as we make a page together.