strong force electromagnetism weak force gravity.
The strong interaction is very strong but very short-ranged. It acts only over ranges of order ##10^-13## centimeters and is responsible for holding the nuclei of atoms together. It is basically attractive but can be effectively repulsive in some circumstances.
The electromagnetic force causes electric and magnetic effects such as the repulsion between like electrical charges or the interaction of bar magnets. It is long-ranged but much weaker than the strong force. It can be attractive or repulsive and acts only between pieces of matter carrying electrical charge.
The weak force is responsible for radioactive decay and neutrino interactions. It has a very short range and as its name indicates it is very weak.
The gravitational force is weak but very long ranged. Furthermore it is always attractive and acts between any two pieces of matter in the Universe since mass is its source.
http://csep10.phys.utk.edu/astr162/lect/cosmology/forces.html