Neotropical refers to one of the eight biogeographic regions of the world. Specifically the neotropics are the region of the New World stretching from central Mexico southward through Central America and most of South America. It also includes the West Indies and southern Florida. The neotropics is delineated by similarities in flora and fauna and is characterized by having much of the worlds' remaining rain and cloud forests.
Tropical refers to a geographic band circling the earth between 23.5 ~ north and south of the equator and delineated by the Tropics of Cancer and Capricorn. The region includes some of the neotropics but not all. The tropics contain over one-third of the world's land mass.