Fundamentals Forces

The Strong Force
A force which can hold a nucleus together against the enormous forces of repulsion of the protons is strong indeed.
It has a very short range.
An exchange force in which the exchange particles are pions and other heavier particles.
It is the strongest of the four fundamental forces

The Electromagnetic Force
One of the four fundamental forces, the electromagnetic force manifests itself through the forces between charges (Coulomb's Law) and the magnetic force, both of which are summarized in the Lorentz force law.
Fundamentally, both magnetic and electric forces are manifestations of an exchange force involving the exchange of photons.
The electromagnetic force is a force of infinite range which obeys the inverse square law, and is of the same form as the gravity force.
In fact, the forces of electric attraction and repulsion of electric charges are so dominant over the other three fundamental forces that they can be considered to be negligible as determiners of atomic and molecular structure.

The Weak Force
One of the four fundamental forces, the weak interaction involves the exchange of the intermediate vector bosons, the W and the Z. It is crucial to the structure of the universe: It is necessary for the buildup of heavy nuclei.
The weak interaction is the only process in which a quark can change to another quark, or a lepton to another lepton - the so-called "flavor changes".
The discovery of the W and Z particles in 1983 was hailed as a confirmation of the theories which connect the weak force to the electromagnetic force in electroweak unification.
Gravity
Gravity is the weakest of the four fundamental forces, yet it is the dominant force in the universe for shaping the large scale structure of galaxies, stars, etc.
The gravitational force between two masses m1 and m2 is given by the relationship:

Viewed as an exchange force, the mass less exchange particle is called the graviton.