Okay, let me explain iso 3166-2:nr to you as if you were 5 years old. Imagine you have a big book with all the names of countries in the world. Now, each country has its own name, but sometimes there are places within a country that also have their own names, like states or provinces.
Iso 3166-2:nr is a special code that helps us identify those smaller places within a country. The "iso" part just means that it's an internationally recognized code system. The "3166" part means that it's about countries, and the "2" means that we're talking about the subdivisions within each country.
Now, "nr" stands for Nauru, which is a very small island nation in the Pacific Ocean. So iso 3166-2:nr specifically refers to the codes that are used to identify the different regions within Nauru.
In other words, it's a way to organize information about the different parts of a country, so that we can easily tell them apart and keep track of them. Pretty cool, right?