What does the nucleus of an atom contain?
Together these particles constitute most of the mass of an atom.
The designation of protons as nuclear particles that possess a positive electronic charge, and electrons as extra-nuclear particles of negative electronic charge, is only of historical significance: the point is that they have OPPOSITE electronic charge. It would have made more sense to designate the electronic charge as POSITIVE, and the nuclear charge as NEGATIVE....but we are stuck with the original designation now.
At extremely short nuclear ranges, protons, and neutrons, confined in the nucleus, engage in the strong nuclear force, the which at this range is strong enuff to overcome the electrostatic force of attraction between LIKE charges.