Layers are the most important element of your image composite. When you import an image into Photoshop on the web, you begin with a single layer, which you can find within the Layers panel on the taskbar, but you're not limited to just one. Layers are arranged in a stack and can be viewed by selecting the detailed layer view from the taskbar in the workspace. Layers can also be quickly added and rearranged by dragging them up or down within your Layers panel. At any point, you can choose to hide or even delete, if necessary.
With Photoshop on the web, it is easy to confirm which layer you're actively working on with Photoshop on the web.