Final answer:
The common aspect typically shared among different healthcare models is the philosophical approaches to healthcare, emphasizing shared principles and values.
Step-by-step explanation:
When summarizing the commonalities (similarities) of healthcare models, the aspect typically shared among them is b) Philosophical approaches to healthcare. This encompasses the shared basic principles or beliefs about how healthcare should be administered and the extent to which healthcare is considered a basic right versus a service to be purchased. Despite different funding mechanisms, cost structures, technological advances, and patient demographics, the underlying philosophies towards healthcare, such as the prioritization of patient well-being and access to care, are commonly held values across various systems.