ABSTRACT
The main purpose of physics is to explain all natural phenomena by means of a few simple fundamental principles. Since all matter consists of particles, then elementary particles physics must give the final answer. By this, one of the main subjects is the question about the nature of interactions. It appears that despite of the diversity of the world surrounding us, all interactions are reduced to four fundamental types, which differ greatly in intensity of their proceeding. Such a classification is not free from some conventionality due to the fact that the relative role of different interactions is changed while the energy of interacting particles grows. It means that the separation of interactions into classes, based on the comparison of processes intensity, can be made reliably only for not very high energies. Let us consider the types of fundamental interactions in order of decreasing their intensity.
