Why FET is less noisy than BJT

Hi All,

I have read the following statemet that the FET is less noisy than BJT. What is this noise exactly? And what is the main reason for this? How do you exactly measure this noise, do we have any specific tools to measure this noise?

Could somebody please explain me this?

Thanks in advance,
Regards,
Satya

I found this which might help: https://www.electro-tech-online.com/custompdfs/2012/05/noise_b.pdf