Some islands are formed due to geological processes like volcanic and sedimentary activities. Volcanic islands, for example, are formed when underwater volcanoes pour magma and rock materials, which cool and solidify until they emerge from the water., Islands like Hawaii, Iceland, and the Galapagos Islands are prime examples of volcanic islands. These islands are formed when magma erupts from the ocean floor, cools, and gradually builds up over time, eventually rising above sea level., There are different types of islands, and they form in various ways, whether through the accumulation of volcanic materials, the shifting of tectonic plates, or the sculpting actions of ice ages and sea-level changes., Discover the natural processes behind how islands are formed and the types of islands that exist around the world., Ocean islands are basically divided into three types: 1) "low" coral and sand islands; 2) "high" islands (usually exposed peaks and ridge-tops of submerged mountains and volcanos); and 3) parts of the continental shelf., An island or isle is a piece of land, distinct from a continent, completely surrounded by water. There are continental islands, which were formed by being split from a continent by plate tectonics, and oceanic islands, which have never been part of a continent..