A Doctorate's degree usually takes 8-10 years. Commonly know as Ph.D (Doctor of Philosophy), there are a variety of other Doctorate degrees by profession, such as Doctor of Theology and Doctor of Physical Therapy. Most demanding professions, such as that of a Doctor or College Professor, require a Doctorate's degree.
There are different doctorate/doctoral degree designations. There are the "professional" degrees such as the MD (Doctor of Medicine), DO (Doctor of Osteopathic Medicine), JD (Doctor of Jurisprudence-law degree), DDS (Doctor of Dental Surgery-Dental degree) PharmD (Doctor of Pharmacy), and PhD (Doctor of Philosophy-often a research doctorate), EDD (Doctorate of Education) DS (Doctor of Science), DMA (Doctorate of Musical Arts), and perhaps other designations.
The MD and DO medical degrees require four years of medical school after a Bachelor's degree. That will be followed by a residency of three to five or more years to focus on a specialization. There may also be additional training required for certain specializations. The JD (Law degree) is typically three years of full time study after a Bachelor's degree. The DDS (Dentist) degree is generally four years after the Bachelor degree, though certain sub-specializations may take longer. The Pharm D, pharmacy doctorate is typically a four or five year program. The Ph.D. is a degree whereby the recipient is trained to do research and to teach. The Ph.D. is required for certain governmental positions and is an educational requirement at most for senior level positions whether administrative or academic.