Gravity is not generated by anything specific inside the Earth. Instead, gravity is a fundamental force of nature that exists between all objects with mass. The Earth, being a massive object, has its own gravitational field that extends into space.
The force of gravity arises due to the warping of spacetime caused by mass and energy. According to Einstein's theory of general relativity, mass and energy curve the fabric of spacetime, creating a gravitational field. Any object with mass, such as the Earth, creates this curvature in spacetime, and other objects nearby are influenced by this curvature, causing them to experience the force of gravity.
In the case of the Earth, its mass generates a gravitational field that pulls objects towards its center. This is why we experience the sensation of weight on the surface of the Earth. The strength of the gravitational force depends on the mass of the Earth and the distance between an object and the Earth's center. The closer an object is to the Earth, the stronger the gravitational force it experiences.
It's important to note that gravity is a universal force that operates between all objects in the universe, not just between objects within the Earth. The Earth's gravity affects objects on its surface, in its atmosphere, and even objects in space surrounding it, such as the Moon, satellites, and spacecraft.