What is ARIN and what is it for?

The American Registry for Internet Numbers (ARIN) is the regional Internet registry for Canada, the United States, and many Caribbean and North Atlantic islands. Only ARIN is responsible for the information about the requested IP address.
 
There are a number of different websites on web that relate IPs and countries. All of these sites use the ARIN database, which they then store for themselves and correcting. Quite often, such bases are outdated, rarely updated. It should also be noted that the definition of countries works differently. Some sites use the country parameter, others geoloc, others use the subnet owner address. Therefore, the country definition (GeoIP) can be done wrong.
 
If you want to look at the IP address information more properly use the ARIN website - https://search.arin.net/rdap/
You can also use our website - https://eurohoster.org/en/ipinfo
 
Moreover, all of the above is quite subjective. For example, a hosting provider may be from Austria, country may be specified as NL, and the server may be in France. GeoIP can be defined as AT, NL or FR.