A lot of enterprises define “country” as “has its own ISO 3166-1 country code”. ISO 3166-1 includes 249 entries: sovereign states, their dependent territories, and “areas of special geographic interest” (e.g. Antarctica).
The English term “country” is ambiguous. In a narrow sense it means only sovereign states, but in a broader sense includes overseas territories and even some subnational divisions (e.g. the four countries that make up the UK)
