[en] In a brief introduction the main aspects of neutron stars and black holes, and their place in the history of astronomy are presented. Stellar evolution is then discussed, energy production through thermonuclear reactions, nucleosynthesis, and stellar structure. The laws for hot gases are also discussed, and applied to main series stars. Pauli's exclusion princip and the degeneration of an electron gas are also treated. The laws for a cold materi are then discussed, leading to release of neutrons at the NDP. Considerations of hydrostatic balance and stability are presented for spherical stars, and finally the development towards the end phase, collapse, leading to white dwarfs, neutron stars and black holes is treated. (JIW)