Why do Philippine called archipelago?

Archipelago is a group, cluster, chain or collection of islands. It is a sea studded with islands. It came from the Greek Word ἄρχι (pronounced as Arkhi) meaning chief and πέλαγος (pronounced as pélagos) meaning sea. Although we have 3 main islands (Luzon, Visayas, Mindanao), Philippines is still an archipelago since we have many clusters or studded islands.