There isn't a model of the Earth called the "round model." The Earth is, of course, a sphere, but the term "round model" isn't used in any scientific context.

Perhaps you're thinking of:

* The Geocentric Model: This model, proposed by ancient Greek astronomers, placed the Earth at the center of the universe, with the Sun, Moon, planets, and stars orbiting it. This model was eventually replaced by the heliocentric model, which places the Sun at the center of the solar system.

* The Heliocentric Model: This model, first proposed by Nicolaus Copernicus in the 16th century, places the Sun at the center of the solar system, with the Earth and other planets orbiting it. This model is the one we use today.

* Models of the Earth's Interior: There are various models that describe the different layers of the Earth's interior, including the crust, mantle, outer core, and inner core. These models are based on scientific data gathered from various sources, including seismic waves, magnetic fields, and rock samples.

If you can provide more context about what you're looking for, I might be able to offer a more precise answer.