Explanation
Our Earth is best described as a "Geoid."
A geoid is a three-dimensional shape that represents the Earth's gravitational field and the distribution of its mass. It closely approximates the Earth's true shape, which is slightly flattened at the poles and bulging at the equator. The geoid accounts for the irregularities and variations in the Earth's surface and gravitational field caused by factors such as the rotation of the Earth, uneven distribution of landmasses, and variations in the density of Earth's materials.
While the Earth is not a perfect sphere, it is also not an ellipse or a parabola. It is best represented by the geoid shape, which takes into account the Earth's complex and irregular nature.