When discussing positively charged particles, it is normally in reference to the proton part of an atom. These positively charged particles make up half the nucleus of an atom.
A proton particle is much larger than the electrons that circle around the nucleus of an atom, but they are similar in size to the neutrons. The neutrons hold the opposite charge to a proton. The balance of protons and neutrons is held in place by a strong nuclear force in the nucleus. The protons and neutrons are generally equal in number, but some elements do have more of one than the other. The protons and neutrons makes up the majority of the mass in an atom as well.