native vs primary

[regcl]

I have been using gnus to hack away at my mail for about a year. Now I am
trying to understand it ...

Looking at the doc, "primary" seems to mean whatever gnus-select-method
points to which could be news or mail.

"native" is a confusingly similar term.

M-x A primary RET, produces 0 hits 

M-x A native RET, produces 1 hit ...

   gnus-group-clear-data-on-native-groups M-x ... RET
       Clear all marks and read ranges from all native groups.

I can't find "primary" in gnus.el, where "native" seems to mean
"primary".

Is there any difference between "primary" and "native"?

Could we simplify the doc by bulk replacing "primary" with "native"?

Thanks,
regcl