Teacher status
Teachers who attend classes by correspondence are not necessarily teachers of issuing schools. Teachers in distance education classes are teachers in license-issuing schools (under normal circumstances, teachers are rarely invited to attend classes outside).
Classroom model
Correspondence courses must be concentrated, and there are twenty days in a semester. Generally speaking, distance education does not focus on classes. Only classes or cram schools with low clearance rate will concentrate on several classes, but it is not strictly required. Usually I take classes online.
Learning style
Correspondence and distance learning are the same, teaching and examination are not divided, so the pass rate is higher than that of self-taught examination!