A proton consists of three theoretical particles: two up quarks and one down quark. The strong force binds the quarks together as a proton. The strong force, as the names implies, is very strong, but has a very limited range, just a little more than a proton or a neutron. The strong force also binds the three quarks in a neutron, two down quarks and one up quark. The residual strong force is that force which extends to the next-door nucleons (nuclons are protons and neutrons) and hold the nucleus together.
A proton consists of two up quarks and one down quark. An up quark caries a charge of +2/3, while a down quark caries a charge of -1/3. Two ups and a down together have a charge of +1, what we observe for a proton. A neutron consists of two down quarks and an up quark, which gives a charge of zero, again what is observed for a neutron.
Therefore, the strong force holds protons and neutrons together by binding the quarks which make up the subatomic particles, and the residual strong force extends to adjacent protons and neutrons and holds the nucleus together.
The weak force is involved in the decay of a neutron to make a proton and a beta particle (an electron), and involves changes in the quarks.
0n1 --> 1p1 + -1e0 + v* ................... 0n1 = neutron, 1p1 = proton, -1e0 = electron, v* = antineutrino