What populations have primarily been incarcerated in correction systems throughout the world? Why? What are prisons like generally in other countries?
In countries which are not democracies, prisons are filled with political prisoners, prisoners deemed as a threat to the political party or dictator in charge of the country. Along similar lines, there are religious persecutions in certain countries by the predominant religion; people of the minority religions may easily end up in prison.
Throughout the world there is the lower element of the society that is involved in all manner of crime, such as drug trafficking, robberies, murders, sexual predatory crimes, etc. These compose the majority of prisoners in almost every country. (In the U.S. in 2005 a report shows that 687,700 state prisons are serving time for violent crimes.)
Prisons in other countries vary by the degree of economic development in the country and its form of government. European nations, such as Sweden, England, and so forth are very similar to those in the United States. However, in third world countries, the prisons are barabaric and inmates are subjected to torture of the cruelest kind. Often the stay of prisoners there will be dependent upon the amount of money that can be supplied to those in charge.
In countries such as China, prisoners--many of whom are politicial prisoners--occupy a small room and are very regimented in their activities. They must rise early and march and exercise. The prisoners work long and hard for virtually nothing. For example, inmates in China "cut" the grass of the prison by squatting and breaking off the grass by hand.
On the other hand, in the federal prisons of the U. S., inmates can work for a small salary in UNICORE (Federal Prisons Industries). They can also learn a trade and they can earn GEDs and take correspondence college courses so that they will be better prepared to return to society.