A graviton is a theoretical elementary particle that mediates the force of gravity in quantum field theory. It is predicted by some models of quantum gravity, which aim to unify general relativity and quantum mechanics. Gravitons are thought to be massless and travel at the speed of light, similar to other force-carrying particles like photons, which mediate the electromagnetic force. Despite extensive research, gravitons have not yet been observed experimentally. Their existence remains a topic of debate among physicists, particularly in the context of theories such as string theory and loop quantum gravity. Understanding gravitons could provide deeper insights into the fundamental nature of gravity and the universe.