Post count.
Validating: Have not validated their email
Partial Member: Less than 200 posts
Super member: More than 200 posts
Member: I think this is depreciated?
Admins are selected by the owner of the site with input from other admins. It is made on the choice of how helpful you are in the community- posts, uploads, answers etc. It also comes with trust- admins have great power and the owner has to know he can trust the admins not to do anything malicious. Considering we may have never met before this is a hard task and usually comes with time. It took me at least a couple of years to get Admin status. Not everyone takes this long though. Not everyone becomes an Admin either. In fact i got my SA status after I "helped" (quotes as i did nothing in reality) the owner create the automatic preview generator and theme protector.
Usually it goes JA to SA but this has its exception. E.g. Vlammetje and ArthurWill went straight into an SA position
