All the commands for creating and working with layers are available in the Layers palette. Each layer has a layer name and its own unique settings that define how the layer interacts with other layers. The layer type is identified by the appropriate icon to the left of the icon name.
There is no way to convert layers to a different type. Each layer holds a unique set of content.
When you click the New Layer button at the top of the Layers palette, a small pop-up menu, shown in Figure 4.2, appears from which you can select the type of layer you want to create. When a new layer is created, it is automatically added directly above the currently selected layer. New layers are automatically named