A dedicated audio cdr,is mainly for use in a standalone cd-copier.(although you can use it in a computer too)
Those standalones can’t write to a ‘normal’ data cdr.
The difference with the audio cd-r and a cd-r is that
there is a flag written to the audio disk before you buy it.
The consumer CD recorders require this flag to be
present in order to record,if they don’t find it on the empty media,they will refuse to burn it.
Empty media,dedicated for audio, costs more,because there’s a fee included for the copyrightholders.
As for quality of the recording,there’s no difference…