ஒரு நாடானது ஒரு [[தீவு|தீவினிலோ]] அல்லது ஒரு தீவுக்கூட்டத்திலோ முழுமையாக அடங்கியிருந்தால் அது '''தீவு தேசம்''' அல்லது '''தீவு நாடு''' எனப்படுகிறது. உலகில் மொத்தமுள்ள நாடுகளில் 47 நாடுகள் தீவு நாடுகள் ஆகும். இவற்றில் பெரும்பாலானவை சிறியவை ஆகும்.
Island nations can be divided in two approximate groups. There are those that are large, relatively populous, and usually close to a [[continent]]. These include the [[United Kingdom]], [[Japan]], [[Indonesia]], the [[Philippines]], and [[Madagascar]]. These countries typically share cultural and political similarities with their continental neighbours. Their island status has sometimes been an important advantage that has isolated them from invasion and made them important in regional trade because of their locations and the maritime abilities of the population. [[Australia]] can be considered this category of nation taken to an extreme: an island nation so large it is considered a [[continent]].
Smaller island nations such as the [[Comoros]], the [[Bahamas]], [[Tonga]], and the [[Maldives]] tend to be very different from continental nations. The small size usually means there is little agricultural land and rarely many [[natural resource]]s. However, in modern times smaller island nations around the world have become centres for [[tourism]], which in many is today the dominant industry.
Some island nations are centered on one or two major islands, such as the [[United Kingdom]] and [[Fiji]]. Others are spread out over hundreds or thousands of smaller islands, such as [[Indonesia]] or the [[Maldives]]. Some island nations share their islands with other countries; these include the [[Republic of Ireland]], [[Haiti]], and [[Papua New Guinea]]. The opposite of an island nation is a [[landlocked]] one.
