Frankly, I think Michigan's terminology on this subject is silly and confusing.
Formally speaking, there are two types of "powers of attorney", one being a "Durable Power of Attorney", and the other being a "Durable Power of Attorney For Health Care". These terms are similar enough to be confusing, and wordy enough to be off-putting.
I prefer using the unofficial terms of "Financial Power of Attorney" and "Medical Power of Attorney"; I believe these terms eliminate confusion, and help move the conversation forward more easily.
Also, the person given the authority under a POA, is referred to in Michigan law as an "attorney-in-fact", even though IN FACT, the person may well not be an attorney. They may even refer to themselves as "the Power of Attorney".
What they really are is an agent, and therefore, I ditch the legalese, and use the term, "agent".
Also, what I call "Financial Powers of Attorney", can be drafted to be "effective on execution", or "effective on disability". Most people choose the latter form, making the grant of authority effective, only once the principal (again, the person giving the authority to someone else), becomes disabled. Often the definition of disability is spelled out in the POA (power of attorney) document; it may require a doctor's written opinion, or there may be other definitions of disability".
A financial POA "effective on execution", is used where the principal is of sound mind (as they must be to sign these documents), but is physically incapacitated to the point, where they simply cannot keep up with their business affairs.