wpa_supplicant.conf entries?

Question

Every resource I have seen / used always say how to COPY or paste entries into wpa_supplicant.conf.

The question is

Is there a document actually explaining , in "5 W's" style, purpose these entries?

I am enclosing annotated entries in my wpa_supplicant.conf to illustrate my post questions.

This is an original with single network entry:

#default original /etc/wpa_supplicant.conf network={ ssid="mywireless" #psk="secretpassphrase" psk=7b271c9a7c8a6ac07d12403a1f0792d7d92b5957ff8dfd56481ced43ec6a6515 }

#temporary commented out

Now what is the purpose of this ctrl_interface and where did it come from ?

#ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev

What are we updating and when ??

#update_config=1

Now for change - this is selfexplanatory #country=US

#network={

# ssid="testing" # psk="jim" # }

Answer 1

On a Raspberry Pi the software release is contained in /etc/os-release. You can get it with:

rpi ~$ cat /etc/os-release