The second and third sentences are called supporting sentences. They are called supporting because they support, or explain, the idea expressed in the topic sentence. Of course, paragraphs in English often have more than two supporting ideas. The paragraph above is actually a very short paragraph.
An academic degree is the state of recognized completion of studies at a school or university. A diploma is generally issued in recognition of having satisfactorily completed the prescribed course of study. special kind of examination is the Staatsexamen. It is not an academic degree but a government licensing examination that future doctors, dentists, teachers, lawyers (solicitors), judges, public prosecutors, patent attorneys, and pharmacists have to pass in order to be eligible to work in their profession.
Graduate certificates vs. master's degrees. A master's degree is typically a two-year, full-time commitment beyond a bachelor's degree in a field of study. Students can obtain a Master of Arts or Science or a degree that is more specialized, such as a master of social work, or MSW, or a Master of Business Administration, or MBA. On the other hand, a graduate certificate -- also called a diploma -- is a short program of study in a particular subject.