It’s basically meditation in movement plus working with qi (energy of the body)
sōng (often written in English as sung): the core word for “release/soften/relax” without collapsing
tīng (short form people say): “listen” = sense/attend internally (micro-tension, weight shift, stacking).
Qi gong Qi (气) literally means "life force" or "vital energy," and "gong" means "work" or "cultivation.