the so-called 128kb should be said to be 128kbps, that is, the code stream rate of the song, and it can also be understood that the size of the parsed sound file is 128kb per second (note: 1B=8b, where b stands for byte and b stands for bit, meaning "bit"). The larger this value, the better the sound quality of the song, and the more space it takes up.

44.1KHz refers to the sampling frequency of songs, which means that the number of times of sound analysis per second is 44.1k..