What do you call an invisible layer that has all the properties of a visible layer allowing it to parent other layers in the composition?

The correct term for an invisible layer that possesses all the properties of a visible layer, enabling it to parent other layers in the composition, is a Null Object. In Adobe After Effects, a Null Object serves as a non-rendering layer that can be used to control the position, rotation, and scale of other layers when they are parented to it. This functionality allows for complex animations and layer management while keeping the composition organized.

By using a Null Object, animators can pivot multiple layers around a central point without the need for visible objects in the composition, making it an efficient tool for achieving desired motion and transformations. This is particularly useful in scenarios where precise control is required without cluttering the scene with additional graphic elements.

The other options refer to different functionalities: an Adjustment Layer applies effects to layers beneath it, an Overlay Layer is typically associated with compositing techniques, and a Master Layer is not a defined term within After Effects. Each serves a different purpose, emphasizing that the Null Object specifically caters to the need for a non-visible control layer.