ISO 3166-2 is part of the ISO 3166 standard, which defines codes for the names of countries and their subdivisions. Specifically, ISO 3166-2 provides codes for the principal subdivisions, such as states or provinces, of countries. Each code consists of a two-letter country code followed by a hyphen and a two or three-letter subdivision code. This standard helps in identifying regions within countries for various purposes, including data processing and international communication. For example, the code for California in the United States is US-CA, where US represents the United States and CA stands for California.