Sample Rate, Bit Depth and Bit Rate
Sample Rate
Sample rate is the amount of samples in an audio per second.This is normally measured in kHz or Hz.The more samples you have in a second the better quality the audio will be.For example an audio which has 44 100 Hz or 44.1 kHz will have better quality audio than a kHz AUDIO.
If you have a music file and you want compress using lossy compression then the quality of the sound will go down. So if the file was originally 44 100 sample rates per second when you compress it it might 20000 sample rates per second.
Bit depth
Bit depth is the number of bits in a sample.The number of bits there are in an audio the more crisp and clear the audio will be.For example an audio with 24 Bits will be better than an audio with 8-bits.
For example if you listen to an Audio with 24 bits will sound crisp and clear but if you listen to the same audio but with a lower bit depth there might be a little distortion when you play the sound.
If an audio is more than 16 bits there are some sounds that the human ear can not hear.So it does not make the quality of audio sound better if it is over 16 bits because we wont be able to hear the other sounds.
Bit rate
Bit rate tells us how many bits are being processed every second.This is measured in kilo bits per second (KBPS).There is a formula to work out kbps and it is sample rate x bit depth x channels= bit rate.For example if an audio has 44 100 samples per second, 2 channels and has 16 bits per sample than the bit rate will be 1,411,200 bits per second.The more samples per second you have and the bits you have the more bigger the file size will be.