Onion model

The onion model is a graph-based diagram and conceptual model for describing relationships among levels of a hierarchy, evoking a metaphor of the layered "shells" exposed when an onion (or other concentric assembly of spheroidal objects) is bisected by a plane that intersects the center or the innermost shell.

Such formats supported by Microsoft PowerPoint's SmartArt wizard invoke the term "stacked Venn".

An onion diagram is a kind of chart that shows the dependencies among parts of an organization or process.

[citation needed] A simple example is to start with the program, operating system and hardware layers.

There is also the cultural or personal identity onion model which has various layers such as environment, behaviors, feelings, beliefs, worldview, and ultimate allegiance or mission.