Classical recording on tape was analog, no bits, no sampling rate.
Digital audio on tape also exists (e.g. DAT) using different sampling rates, e.g. 48, 44.1 or 32 kHz.
the higher samples / sec gives a higher audio quality
The DVD has the storage capacity for the higher sample rate than what a CD does, so they make use of that extra space
ohhh and DVD audio sample rates are not fixed at 4800 sps, there are considerably higher rates used as well