Atomic nuclei are made of nucleons, protons and neutrons, composed of quarks strongly interacting via gluons. "How such complex objects as particles and nuclei are built?", remains a fundamental question. A new 'frontier' of subatomic physics is the exploration of exotic nuclei, elements and isotopes not stable enough to have survived on Earth. Exotic nuclei populate vast unknown regions of the nuclear chart where many unexpected structures have recently been discovered. Exotic nuclei synthesized in laboratory allow large variation of the neutron and proton chemical composition of nuclear systems needed to uncover the true nature of the subatomic structures and to understand the origin of elements in the Universe.