How and why does the physical geography of Martinique differ from that of the Cayman Islands?

Martinique is an island in the Eastern Caribbean. It is a volcanic island formed by the subduction of the South American Plate beneath the Caribbean plate. Mount Pelee is the resident volcano on the island. Cayman islands and predominantly coral islands that are relatively flat and devoid of surface drainage. The differences in the physical geography is because of the location of each island in relation to a tectonic boundary ad the subsequent processes that occur there.