International differences between "adjunct professor" and "visiting professor"? I am interested in the differences between levels of professorships in the countries:


USA
UK
China
Germany


I read the Wikipedia Article about Professorship in United States but as far as I can tell - in the end - both take up the position of a professor:


for a (short) time - but tend to stay for quite a while, even if that is not the idea (both possibly receiving bad contracts)
which is non-tenure track,
are not involved in administrative tasks,
might come from a different university, but don't have to.


In an international context: What is the difference between an "adjunct professor" and a "visiting professor"?

Additionally: Which one is more prestigious?
In the United States, "Adjunct Professor" is essentially an academic temp worker.  They are typically paid very poorly, have no job security, and often live near or below the poverty line.  They are often not well respected, particularly as many faculty perceive them as either a threat (administrators often use adjuncts to avoid making tenure-track appointments) or as a source of cheap labor.

A "Visiting Professor" on the other hand, typically means somebody who has a position elsewhere and is temporarily associated with the faculty, e.g., while on sabbatical or as a courtesy appointment for a person from industry who is teaching a course.  A visiting professor might or might not draw any salary from the university, depending on the particulars of their appointment.  Their status and degree of respect generally depend on their main position.

Note, however, that this vocabulary is not legally protected, and so some US institutions may change these titles around, particularly if they are seeking to camouflage the nature of an poorly paid post.