Unlike in Photoshop, where it is common to have dozens of layers, InDesign documents typically have few layers. Some users even get by with the one default layer with the inspired name “Layer 1.” They can do so because each item on a spread is merely content in a layer, rather than a layer itself, as it would be in Photoshop. Commands like Object > Arrange > Send to Back give us a way to control stacking order and position items visually below or behind others. But as a document becomes more complex, layers give us greater control, and not just for stacking, although that’s a fine place to start.
To the left of a layer’s ...