What is the meaning of 'national' as in eg 'Australian national'? [closed]

From here: https://academia.stackexchange.com/questions/115930/career-prospects-for-a-math-phd-student-in-pure-math

I am an Australian national and want to live in Australia long term.

what exactly is the meaning of Australian national? like student visa? or actual citizen? or resident?

Solution 1:

Australian national = Someone entitled to an Australian passport.

In British and Commonwealth law a national of a given country is the only type of person entitled to a passport of that country.

The right to a passport is governed by the laws of the country. It may be by descent from a national or birth in the country (or one of its territories) or may be granted (or withdrawn) by the government of the country.

(Source 40 years of dealing with questions of nationality.)