Apple Motion 5.1.1 - Manual (Page 154)

Chapter 6 Create and manage projects 154
Layers, in turn, are nested in containers known as groups. When you create a layer, that layer is
placed inside a group. You can drag a layer from one group to another, but layers cannot exist
on their own, outside a group. Layers nested inside groups appear indented in the Layers list
and Timeline.
Nested layers
Enclosing group
A group can also contain other groups nested inside it. In this way, you can construct complex
hierarchies of nested groups, with each nested group subordinate to the group that contains it.
Enclosing
group
Nested groups
It’s a good idea to group layers that work together as a unit. Doing so ensures that animation
and effects applied to the enclosing group affect all layers nested in that group. By nesting
related layers you want to animate inside a group, you can save time by animating the enclosing
group, instead of animating each layer.
67% resize factor