Unlike many career fields, there is a relatively small variation in the types of appointments for faculty members in colleges and universities. However, I often find that many non-faculty have a hard time understanding the different types of appointments used in higher education. Once you understand the basic underlying structure for appointments, it is easy to quickly figure out the types of faculty appointments in higher education.
I think much of the confusion regarding faculty appointments comes from the fact that different institutions used slightly different names to describe the appointments. Despite this, the basic structure of appointments does not vary tremendously between institutions.