Hi OP, just a warning that this subreddit has a rule against discussing current affairs, which for our purposes is defined as any events and conditions within the last 20 years (1996+). As a result, it's possible that any responses regarding Korean camps might be too outdated(?) to be entirely useful to you.

Oh boy, that is a question...

Well, as far as we can tell - since it is very very hard to get any sort of information on the camp system in North Korea - one of the distinct differences is that the North Koreans do not have extermination camps, i.e. camps with the sole purpose of murdering millions of people.

Death camps during the Holocaust such as the Operation Reinhard camps Sobibor, Treblinka, and Belzec and the death camp in Chelmno had the sole purpose of killing millions of people fast. They were very small - Sobibor for example originally being only 12 hectars big, later expanded to 60 hectars - and consisted basically only of an arrival area, a sort of line area through which prisoners were shuffled and the gas chambers. At the end of the line there was a crematorium complex with a gas chamber functioning on the basis of a Russian tank engine. When trains arrived, the vast majority of the prisoners were shuffled through the line area into the gas chambers and killed immediately. Hardly any prisoners were kept alive for labor purposes and the number of alive prisoners at these camps numbered somewhere in between 150 and 500 at any given point and with those kept alive killed regularly, while the death tolls for these camps number from 250.000 at Sobibor to about 900.000 at Treblinka.

Only Auschwitz (and Majdanek if included, which it not always is because it only served as such a camp for one Nazi action) were different in that it fulfilled the dual purpose of extermination camp facility and concentration camp, i.e. forced labor reservoir and prison. In terms of what we know of the North Korean camps, they have high death tolls and appalling and horrid living conditions but it is not their sole purpose to exterminated millions of people upon arrival at the camp, i.e. gas hundred of thousands of prisoners immediately after arrival.

In terms of cruel and horrendous treatment of prisoners, it seems to me that from the information available the North Koreans are not that dissimilar to the Nazis but structurally speaking, they don't run camps with the sole purpose of the murder of millions. It might seem as a slight or nitpicky differentiation to some and it certainly is not an argument that can be brought up in order to lessen the crimes of the North Korean regime but in terms of historic analysis of the phenomenon this is a difference one needs to account for.

Here is the AMA by Kang Cheol-hwan, the author of The Aquariums of Pyongyang, a book describing his times in the Yodok Prison Camp.

Here is the homepage for the UN Commission of Inquiry on Human Rights in the DPRK. Be warned, if you get into the nitty-gritty details, it can be pretty graphic because you are right: this is happening now. These reports are not talking about 80 years ago, but things that are going on as you read this.

I believe /u/commiespaceinvader covered the Nazi side of things pretty well. I'll try and fill in the blanks on the North Korean side.

From the final UN report:

The police and security forces of the Democratic People’s Republic of Korea systematically employ violence and punishments that amount to gross human rights violations in order to create a climate of fear that pre-empts any challenge to the current system of government and to the ideology underpinning it. The institutions and officials involved are not held accountable. Impunity reigns.

Both the DPRK and the Nazis were systematic in employing violence and punishments that were/are gross human rights violations. The DPRK, however, is using this violence and fear for political survival of the regime, not genocide.

The State Security Department, the Ministry of People’s Security and the Korean People’s Army Military Security Command regularly subject persons accused of political crimes to arbitrary arrest and subsequent incommunicado detention for prolonged periods of time.

A big difference between the Nazi's and DPRK is that the DPRK camps are almost entirely politically related, and that people can be and are released (Kang Cheol-hwan was released).

Starvation and other inhumane conditions of detention are deliberately imposed on suspects to increase the pressure on them to confess and to incriminate other persons.

Again, the DPRK is political. The Nazis weren't torturing people or looking for incrimination - being a Jew/Pole/gay/whatever was enough for them. The DPRK doesn't throw people in prison for no reason. They always have a reason, even if that reason is very minor, or unrelated to you, or even made up, but they always have a reason.

In the political prison camps of the Democratic People’s Republic of Korea, the inmate population has been gradually eliminated through deliberate starvation, forced labour, executions, torture, rape and the denial of reproductive rights enforced through punishment, forced abortion and infanticide.

This is probably where the two regimes camps are most similar. The DPRK IS winnowing down the population. Although they aren't gassing people, they are still deliberately killing people.

There are plenty of books on the subject of North Korea and their human rights abuses. The Aquariums of Pyongyang is, in my opinion, the best one. Kang was one of the first people to write about his experiences in the camp system, and his book is very simple. There's not a lot of graphic description or over the top stories. He is very matter-of-fact about his time there. Some of the other books can be a bit much, namely Escape from Camp 14, which has been found to have been... embellished a bit? There's no need to embellish - these stories are horrible enough.

I would also urge you to take a look at the UN information. They held hearings in Seoul in 2014 (as well as a few other places - I live in Seoul, so that's the one I'm familiar with) and you can see some video of the testimony that was given. It's pretty brutal.

TLDR - the DPRK's system is for political prisoners who are all sent there for a reason, as arbitrary as those reasons may be. They do not have death camps, but they do their best to make sure many of the prisoners die.