An archipelago is a chain or cluster of islands. The word archipelago literally means "chief sea", from Italian arcipelago (artʃiˈpelago) , derived ultimately from Greek arkhon (arkhi-) ("leader") and pelagos ("sea"). In Italian, possibly following a tradition of antiquity, the Archipelago (Greek: Αρχιπέλαγος) was the proper name for the Aegean Sea and, later, usage shifted to refer to the Aegean Islands (since the sea is remarkable for its large number of islands). It is now used to generally refer to any island group or, sometimes, to a sea containing a large number of scattered islands like the Aegean Sea.
The five largest modern states that are mainly archipelagos are Japan, the Philippines, New Zealand, the United Kingdom and Indonesia (the world's largest archipelagic state according to the CIA World Factbook)
The largest archipelago in the world by size is the Canadian Arctic Archipelago of Northern Canada. It is situated in the Arctic Ocean. The archipelago with most islands is the Archipelago Sea in Finland, but these islands are, on average, small.