Does anyone know what the Graviton is ?

Answer 1

According to Einstein there are no gravitons.
A graviton is a made up particle to try to explain gravitation in an alternative to Einsteins theory. Nobody knows if gravitons exist.
Many people are sure they do not exist.
Many people try to prove their existence.
Equally difficult it is to prove their non existence.
Perhaps in time, there will be an answer to your question like:
a) They were a fairy tail.
b) They are real and thier features are.......

Answer 2

In physics, the graviton is a hypothetical elementary particle that mediates the force of gravity in the framework of quantum field theory. If it exists, the graviton must be massless (because the gravitational force has unlimited range) and must have a spin of 2 (because gravity is a second-rank tensor field).

Gravitons are postulated because of the great success of the quantum field theory (in particular, the Standard Model) at modeling the behavior of all other forces of nature with similar particles: electromagnetism with the photon, the strong interaction with the gluons, and the weak interaction with the W and Z bosons. In this framework, the gravitational interaction is mediated by gravitons, instead of being described in terms of curved spacetime like in general relativity. In the classical limit, both approaches give identical results.

However, attempts to extend the Standard Model with gravitons run into serious theoretical difficulties at high energies (processes with energies close or above the Planck scale) because of infinities arising due to quantum effects (in technical terms, gravitation is nonrenormalizable.) Some proposed theories of quantum gravity (in particular, string theory) address this issue. In string theory, gravitons (as well as the other particles) are states of strings rather than point particles, and then the infinities do not appear, while the low-energy behavior can still be approximated by a quantum field theory of point particles. In that case, the description in terms of gravitons serves as a low-energy effective theory.

Since gravity is very weak, there is little hope of detecting single gravitons experimentally in the foreseeable future

Answer 3

It is a yet undiscovered particle that applies a force of attraction between two bodies. One of the weak forces.