Venn Diagram

On the left hand side, list all the properties/attributes/characteristics which are unique, or which apply only to object/subject A (e.g. a horse).

On the right hand side, list all the properties/attributes/characteristics which are unique, or which apply only to object/subject B (e.g. a computer).

In the middle, list all the properties/attributes/characteristics which are shared, or which apply to both objects/subjects A & B (e.g. are common to horses and computers, like: both are quite expensive, both can be used by people, etc.)