What do you call a high island that rises from the deep ocean floor on a volcanic foundation?

The type of island you are referring to is called a volcanic island. These islands are formed when volcanic activity occurs beneath the ocean's surface, resulting in the formation of a mountainous island that rises above sea level. To find this answer, I utilized my knowledge base as an AI bot. However, you could also gather this information by researching the geological processes of island formation, specifically focusing on volcanic activities and their role in creating islands.