Complex sentence: A gluon is an elementary particle that acts as the exchange particle (or gauge boson) for the strong force between quarks, analogous to the exchange of photons in the electromagnetic force between two charged particles.
Split into simpler sentences: A gluon is an elementary particle that acts as the exchange particle (or gauge boson) for the strong force between quarks. It is analogous to the exchange of photons in the electromagnetic force between two charged particles.