A synoptic enumeration of the various fields of Modern Physics can be carried out in a increasing length scale, or conversely a declining energy scale, starting from the smallest elements of matter and ending at the Universe itself.

Physics of Elementary Particles or High-Energy Physics: Elementary particles are the focal point of this field which classifies elementary particles according to their properties, like their mass, charge, spin etc., as well as their interactions. The electron, the neutrino, the photons, the quarks and others are considered today as elementary particles. Regarding quarks in particular, they are the building blocks of the proton and the neutron which constitute the nuclei of the various elements, which until recently were considered as elementary entities. Experiments have proved the existence of 37 elementary particles. The Physics of Elementary Particles is the biggest front of the research of the microcosm. Its theoretical tools are Relativity and Quantum Mechanics. Experiments of the High Energy Physics are carried out with gigantic accelerators which normally represent the effect of collective efforts of a big number of research teams from many different countries. A relatively recent major achievement of the Elementary Particle Physics is the unified theory of the electromagnetic and the weak nuclear forces.

Nuclear Physics: A big part of the research in Nuclear Physics today is focused on the topic of radioactive exotic and stable nuclei at high energies and angular momenta. The aim is the study of new forms of nuclear matter, the synthesis of ultra-heavy systems and the study of the origin of elements and the energy generation in stellar interiors. A significant part of the research is invested in the understanding of the nuclear force in the frame of the problem of many particles-nucleons and hadrons and in the study of the role that the nucleus has in electro-weak interactions. Moreover, applied research which concerns other domains like Medicine and Radio-ecology is carried out.

Atomic and Molecular Physics: They are the fields of Physics which study the structure and the properties of atoms and molecules. Modern research in this field is dominated by lasers, setups based on the effect of light amplification by stimulated emission of radiation. Under the influence of strong electromagnetic fields lasers exhibit very interesting properties.

Physics of Condensed Matter: This field studies the various properties of solids or liquids which are formed from a large number of atoms or nuclei and electrons in crystal or amorphous state. It has a huge array of practical applications with very important impact on the technological aspects of every-day life, like the semi-conductors for example. It should be noted that the Physics of Condensed Matter research has led to the discovery of fundamental physical phenomena due to the collective action of a large number of particles, such as superconductivity.

Geophysics and Atmospheric Physics: This field studies the movements of the Earth's crust (Seismology) and magnetic field, as well as the terrestrial atmosphere  and its variations (Meteorology, Climatology, Physics of the Atmospheric Environment) etc. The latter field is of great importance given the increasing societal interest in climate changes due to the influence of several anthropogenic parameters on the environment.                                                 

Astrophysics: This field studies all the heavenly bodies, like the Sun, planets, stars, galaxies, and the Universe itself (Cosmology). This is a rapidly evolving field lately, because of the use of cutting-edge   high-tech experimental and observational setups and of the close collaboration with other fields of Modern Physics such as Elementary Particle Physics, Nuclear Physics etc. On the theoretical end, the study of the evolution of the Universe is the common focal point of Cosmology and Theoretical Elementary Particle Physics.                                   

Gravity and Cosmology: This is a basic field which frequently shaped the course of Physics since its foundations in the Newtonian gravity and the theory of General Relativity (birth of the modern theory of gravity) until today. The traditional basis of cosmological facts is already been reshaped with cutting-edge high precision measurements. Current research focuses on both the smallest length scale which dominated during the first moments after the Bing Bang and on the largest possible length scale in the current Universe. It appears that a necessary condition for the understanding of the Creation is a unified quantum-mechanical description of gravity with other interactions and the uncovering of the mechanisms of time and space creation.