Layers are a basic founding concept you need to understand when working with Photoshop. If you think about layers as several sheets of transparencies, each with a different picture on it, then you can understand layers. Essentially, each layer is one image, or one small part within the bigger or all-encompasing picture. Take the following as an example:

This is layer one. Think about this layer as our first transparency sheet, with a black border and red circle in the upper left hand corner.	This is layer two, a transparency with a green circle in the middle.	This is layer three, our final transparency with a blue circle in the bottom right hand corner.

Now if we put layer 2 (green circle) over layer 1 (red circle) and layer 3 (blue circle) over layer 2, we'll get an overlapping of colors within a single image. That's how layers work. Although understanding layers is simple enough, it is exactly this feature (okay, and a few others) that make Photoshop an industry standard.

This diagram illustrates the features of the Layers palette.

An animated example of the layers concept can be viewed here: Layers Animation

As you can see, there are many features associated with the palette, but here are some of the most used:

• The Layer Lock option enables you to lock specific features within the layer.
• The Layer list displays all of your layers from topmost to bottommost.
• The Eye icon shown to the left of a layer is the Visibility button that controls whether you can see the layer. You can still work on a layer even though you can't see it, however
• The Paintbrush icon next to the Eye icon indicates which layer is currently selected (and therefore capable of being worked on). To select a layer, all you have to do is click on it. Selecting a layer makes it visible.
• Dragging a layer to either to the New/Copy Layer or Delete Layer buttons on the bottom of the palette will copy or delete the layer.
• You can also rearrange layers. For example, in our color circle example, the blue circle could be placed beneath the red and green circles. To do this, you simply click and drag the layer to be above or below other layers in the Layers list.