What is the difference between a protocol, standard of care delivery, and policy at the practice, state, and federal level?

What is the difference between a protocol, standard of care delivery, and policy at the practice, state, and federal level? Briefly outline each. What are the perceptions of the health care delivery system from the perspectives of patients, providers, payers, and policy makers? Discuss at least one perception from one of the populations listed: patient, provider, payer, and policy maker.