Scenes are divided into layers. Layers are populated via collections, and contain the objects that you want to include in your render.
Click on the status line to open the Render Setup editor to create a render layer.
To create a render layer, click . For better organization, you may want to give your render layer the same name as your target rendered image. Upon batch rendering, a separate folder is created for each layer, where the name of the folder is that of the render layer, with a rs_ prefix appended.
You can then create collections for your render layer. See Create a collection for your render layer.
Layers are populated via collections: you do not add objects directly to a layer. You can add the same object to more than one collection.
Here are a couple of typical use cases that explain the benefits of adding objects to a collection rather than directly to a layer:
For more information about collections, see Create a collection for your render layer.
The scene layer, also known as the master layer, controls the scene settings. It is similar to render layers in that you can control its visibility and whether or not it is renderable. Its Render Settings and Lights tabs also allow you to adjust the global Render Settings and global light settings. However, it is different from render layers in that it cannot contain collections or overrides.
The terms scene layer and master layer are used interchangeably.
Only one render layer can be visible at a time, whether it is a render layer you created, or the scene (master) render layer. The layer whose objects are visible in the viewport is denoted with a highlighted icon in the Render Setup editor.
The scene (master) render layer visibility is denoted by the in the Scene settings area, at the top of the Render Setup editor.
To switch to a different render layer, or to the scene (master) layer, click on the layer.