Below is a list of each country along with its ISO Alpha-2, ISO Alpha-3, and ISO Numeric codes. Each of these codes released by the ISO (International Organization for Standardization) has distinct uses.
The Alpha-2 codes are used primarily as top level domain extensions. The Alpha-3 codes offer a closer representation of each country, which are used on passports and by the UN. The numeric codes are useful because they can be used independent of the Latin alphabet.