Unity or proximity is a basic principle of design. Unity works by positioning elements of your design close or far apart depending upon their relationships. The following are some examples of how unity works.
A Simple Example of Unity
When you look at the following two examples, think about what you know about the text simply because of how it's positioned.
Version 1:
My Dogs
- Homer
- Calico
- Mickey
- Shasta
- McKinley
Version 2:
My Dogs
- Homer
- Calico
- Mickey
- Shasta
- McKinley
In the first version, there is one list of dog names. In the second version, you know immediately that there is something different about the second group (Shasta and McKinley). You know this immediately and without even thinking about it, because they are separated from the first group.
The simple act of grouping them together makes them stand out as different from the others. The physical closeness of Shasta to McKinley implies a relationship between those two dogs that isn't there between Homer, Calico, and Mickey.
In case you're wondering, Shasta and McKinley were the first two dogs I didn't share with my parents. The other three dogs were owned by my parents.

