They are called ccTLDs - country code top level domains.
Yes and they get demoted (or omitted entirely) in search results for people outside the country of origin. This means that the domains are only worth something if they can be sold to people doing business in that country. The economy of the country matters a lot and, secondly, your ability to find buyers there.
If there are single world domains available in a particular ccTLD then there must be a good reason for that. Usually it means that the people are too poor, internet penetration rates are too low, online economy is too small and so on and on.
In some cases it might be that the ccTLD is not used and people prefer gTLDs like .com. An example of this is .us.