https://helpx.adobe.com/be_en/photoshop/using/add-manage-edit-layers-ipad.html
Learn the basics of working with layers in Photoshop on the iPad.
Learn how to use layers in Photoshop on the iPad to create a composite of multiple images, add text to an image, add vector graphic shapes, and add other...
learn the basicsworking with layers
https://resources.arcgis.com/en/help/main/10.1/0017/001700000073000000.htm
ArcGIS Help 10.1 - Working with layers and table views
Layers and table views are alternative and useful ways to access your data.
working with layersarcgishelptableviews