The "strong fundamental interaction" refers to the force that binds quarks together to form protons and neutrons. Synonyms for this term might include the "strong nuclear force", "strong force", or "strong interaction." These terms are all interchangeable and describe the same phenomenon, which is the attraction between particles that holds the nucleus of an atom together. This fundamental force is essential to the workings of matter, and its strength is what determines the stability of atomic nuclei. Scientists have developed complex models and theories to understand the strong interaction, but it remains one of the most elusive and mysterious forces in the universe.