"What are (A)BJDs?""

Long story short; Asian Ball-Jointed Dolls are dolls with ball-joints that are primarily developed and produced in Asia!

Short story long... well, it's long. I divided it roughly;
A (relatively) short history of the moderne (A)BJD
Resin vs Vinyl; the anatomy of a BJD (under constructions)
Dictionary
(Distant) relatives (under construction)