Could be various things, depending on the country in question and the type of alien residency. Off the top of my head:

* Right to work, accumulate social security/pension rights, work for government entities, security clearance

* Right to own land / property

* No duty to carry an alien registration card at all times / freedom of movement within the country

* Right to marry or (if married to a citizen) keep their children with them if they ever divorce and move back home

* Right to political speech / lobbying

* Right to leave the country and return unconditionally

Those are privileges that come with being a citizen.

The question was what distinguishes a non-citizen from a citizen -- which comes before that.

Then I don't understand the question. Citizenship is a legal status. By definition, any distinction with other statuses will be legal ones: more or less rights (or privileges, if you will) and duties.

>Then I don't understand the question. Citizenship is a legal status.

Depends on the culture.

In ancient Athens, for example, being a citizen was attached to a moral imperative towards your state, not just a mere "legal status".

You were first and foremost a citizen. In fact the opposite, a person concerned with his own affairs first and foremost, was considered by the culture an inferior person, and the word use ("idiotis" -- literary "private/concerned with private affairs"), survives to english as "idiot".

That wasn't the case only in ancient Greece of course. In all kinds of cultures, citizenship and being a citizen, was considered as something bigger than "i got this legal stamp".

By the way, I always thought that "Starship Troopers" were basically ancient Greece replayed in sci-fi setting. In Greece all citizens had to fight for the state, when the need arises (which was happening regularly and the threats were very serious). Sometimes they conscripted slaves, but the slaves were given freedom (or maybe even citizenship) after that.

I don’t know about other countries, but in the US, it’s basically impossible to involuntarily lose citizenship, and citizens have an absolute right to enter the country. Permanent residents can lose their status and get kicked out of the country for various offenses, and can potentially be denied entry for arbitrary reasons.

> in the US, it’s basically impossible to involuntarily lose citizenship

Over the past 20 years, several laws have been passed that erode proof of citizenship:

- id documents with an expiry date are not usable after that date (expired passports used to be accepted for domestic non-travel uses)

- the Evite database decides whether you can work at many companies

- parish records are sometimes deemed unacceptable as proof of birth, disallowing the reissue of other documents like passports

- some people have duplicate SSNs

- in the past year, a small number of people in both the USA and Canada have been told their original and valid citizenship documents were not valid by Immigration, with the burden of proof on the citizens.

Compare that to losing one’s permanent residency, which can happen because of something as simple as forgetting to tell the government that you’ve moved.

Non-citizens can vote, sometimes. I’m an Irish citizen, but if I moved to the UK, I could vote in mostelections there.

Edit: also, obviously, not all citizens can vote. Children can’t, historically women couldn’t, some countries used to have racial and/or economic qualifications, and some countries still don’t allow people who’ve committed crimes to vote.

Here in NZ noncitizen legal permanent residents who have met a minimum residency can vote .... no taxation without representation and all that (something that the US has sadly forgotten)

Clearly that right to vote comes from your citizenship.