How does Middle America differ from Central America?

The terms "Middle America" and "Central America" are often used to describe regions within the Americas, but they differ in their geographic scope.

Middle America is a broad designation for the isthmian region stretching from the southern border of the United States to the northern border of Colombia. This region encompasses Mexico, the countries of Central America, and, according to some definitions, the West Indies.12

Central America, by contrast, is a more specific geographic region that comprises seven countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama. While some geographers extend the northern boundary of Central America to the Isthmus of Tehuantepec in Mexico, the primary distinction is that Middle America explicitly includes the entirety of Mexico, whereas Central America is generally defined as the region south of Mexico.312