Terminology
Volksdeutsche "ethnic Germans" is a historical term which arose in the early 20th century and was used by the Nazis to describe ethnic Germans living outside of the German Empire, although many had been in other areas for centuries.
Auslandsdeutsche (adj. auslandsdeutsch) is a concept that connotes German citizens living abroad, or alternatively ethnic Germans entering Germany from abroad. Today, this means citizen of Germany living more or less permanently in another country (including long-term academic exchange lecturers and the like), who are allowed to vote in the Republic's elections, but who usually do not pay taxes to Germany. In a looser but still valid sense, and in general discourse, the word is frequently used in lieu of the ideologically tainted term Volksdeutsche, denoting persons living abroad without German citizenship but defining themselves as Germans (culturally or ethnically speaking).
Read more about this topic: German Diaspora