This paper contains the synopsis of my three lectures given at the XV International Workshop on Hadron Physics. The first lecture covers introduction to the general life cycle of stars and the origin of compact objects, followed by the history of neutron stars (NSs) discovery and their macroscopic features together with a survey of the latest astrophysical observation techniques. The second lecture is devoted to macroscopic and microscopic nuclear physics models of the equation of state governing the cold neutron stars. A special attention is paid to the Quark-Meson-Coupling model, an effective relativistic mean-field model in which the forces between individual baryons are self-consistently mediated by exchange of virtual mesons between the valence quarks in the baryons. In the third lecture (i) similarities and differences between dense matter created in heavy ion collisions and the cores of neutron stars, (ii) gravitational waves from binary neutron star merges and (iii) the impact of data in the multi-messenger era on deeper understanding of neutron star interiors are discussed.