You must first understand the meaning of audio bitrate:

Bitrate "refers to the data flow of audio contained in each sample. The unit is bps"

The bit rate of CD is generally 800Kbps-1200Kbps, which can be understood as lossless sound quality. The higher the bit rate, the larger the audio file size, and the closer the sound quality is to the original sound quality.

The standard sound quality is understood as: a popular song on the Internet is about 4-5MB. The bit rate of mp3 is generally 64 128Kbps. HD can be understood as 320K bps.