Germany
Admission
In Germany a Master, Magister, Diplom or Staatsexamen (state examination) degree is generally required to gain admission to a doctoral program. However, in some cases, good grades or a degree in a related field are additional requirements. The candidate also has to find a tenured professor to serve as the formal advisor on the Dissertation/thesis throughout the doctoral program. An informal term for this advisor is Doktorvater.

In Germany, doctoral programs are generally taking three to five years to complete, but the length strongly depends on the subject. Usually, there are no formal classes, but an independent research is conducted under the tutelage of a single professor. Because of this, a good deal of doctoral candidates is to work as research or teaching assistants - they are paid a reasonably competitive salary. This situation considerable differs from the one in many other countries, U.S. included, where doctoral candidates are often referred to as Ph.D. "students". In the case of German candidates, this term should be avoided because of it inaccuracy.
 
History
In the earlier universities, the Doctorate was awarded as a first degree. Since then, it has evolved into a research degree.

In German-speaking countries, the former Soviet Union, most Eastern European countries, most parts of Asia, Africa, and many Spanish-speaking countries the corresponding degree is simply called "Doctor" and it is clearly distinguished by subject area with a Latin suffix. For example, "Dr. med." is for doctor medicin, which is a scientifical title unlike an M.D.; "Dr. rer. nat." is for doctor rerum naturalium - Doctor of Science; "Dr. phil." is for doctor philosophiae, "Dr. iur." is for doctor iuris (which is not equal to a J.D.),  etc.