DD
Probably Doctor of Divinity.
The acronym for "Doctor" is "Dr."
It means Doctor of Divinity. It is an advanced degree in Divinity. In the United States the Doctor of Divinity is usually awarded as an honorary degree.
Divinitatis Doctor
A Doctor of Divinity degree (DD), is a doctor's degree in religion.
One can get a Doctor of Divinity degree from a university. It can be earned at a university or someone can be awarded an honorary degree from a Christian college.
The acronym DO behind a physician's name stands for Doctor of Osteopathic Medicine.
PhD = Doctor of Philosophy .
Martin Luther King was a Doctor of Divinity.
An aulic is a ceremony in certain European universities to confer a Doctor of Divinity degree.
Neither. He was a Doctor of Divinity (or "Doctor of Sacred Theology", I've found both phrases used and his tombstone says DST).
The acronym "PhD" stands for Doctor of Philosophy. Despite the word "doctor" in the title, a PhD is not the same as a medical doctor. A PhD is a research-focused degree that signifies expertise in a specific academic field, while a medical doctor is trained to diagnose and treat patients.