Groups of islands are called "archipelagoes", for example, the Galapagos islands.
An archipelago.
An archipelago is a chain or cluster of islands.
You likely mean either the Aleutian Islands or Alexander Archipelago.
Aleutian Islands
Home Islands
Archipelago
Galapagos Islands
Chatham Islands Chatham Islands
A chain of islands is often called an "archipelago".
qwreefer
An archipelago is simply a chain of islands. Hawaii would qualify as one.