It's all noise to me really
PCM is the way to digitally represent sampled audio. The two basic properties of it is Sampling frequency and bit depth.
Is how often the audio signal is sampled. Ex 44.1 kHz.
How many bits are used for each sample. Ex 8, 16 or 24.
A PCM stream only encode a single channel (mono). Multichannel audio formats contains more then one PCM stream. The most common format is stereo with two channels.