"Discrete" means that it works on discrete-time signals (sampled data).
d ɪ s k ɹ iː t WORD_BOUNDARY m iː n z WORD_BOUNDARY ð ʌ t ɪ t WORD_BOUNDARY w ɜː k s WORD_BOUNDARY ɔ n WORD_BOUNDARY d ɪ s k ɹ iː t t aɪ m WORD_BOUNDARY s ɪ ɡ n ə l z WORD_BOUNDARY s æ m p ə l d WORD_BOUNDARY d eɪ t ə WORD_BOUNDARY