Guidance or Law??

What is the difference between guidance and a law?? Seems to me a law as such must be obeyed upon penalty for not obeying.

Guidance? Not so much.  Guidance, to me, is simply a recommendation for following a set of "guidelines".

Here is a link to californias guidance for the use of face coverings, from the california dept. of health. In the text it says "It mandates that face coverings be worn state-wide in the circumstances and with the exceptions outlined below." 


So I repeat the question, what is the difference between guidance and the law? And who makes the law, dept. of health or our state legislature?