1. Theoretical and Observational Principles of the Astrophysics of Neutron Stars.- 1.1 Prediction.- 1.2 Accretion.- 1.3 Rotation and Magnetic Field.- 1.4 Radiopulsars.- 1.5 New Ideas.- 1.6 X-Ray Pulsars.- 1.7 X-Ray Bursters.- 1.8 Bursts and Other Sources of Gamma Rays.- 1.9 General View.- 2. Structure of Neutron Stars.- 2.1 Equilibrium of Stars.- 2.2 Exact Equilibrium Equations for Cold Stars.- 2.3 Physical Conditions Inside Neutron Stars.- 2.4 Parameters of Neutron Stars.- 2.5 Mass of Neutron Stars.- 2.6 Rotational Effects.- 3. Fluid Dynamics of Accretion.- 3.1 Spherically Symmetric Accretion.- 3.2 The Role of Radiation and Ejection.- 3.3 Spherical Accretion to a Neutron Star Without a Magnetic Field.- 3.4 Capture of Matter by a Moving Star.- 3.5 Fluid Dynamics of Cylindrical Accretion.- 3.6 Disk Accretion.- 3.7 Luminosity and Spectrum of Accretion Disks.- 3.8 Supercritical Disk Accretion.- 3.9 Accretion in Binary Systems.- 3.10 Two-Stream Accretion.- 3.11 Accretion of Magnetic Fields.- 4. Classification of Neutron Stars.- 4.1 Magnetic Dipole.- 4.2 Stopping Radius.- 4.3 Stopping Radius in the Supercritical Case.- 4.4 The Effect of a Magnetic Field.- 4.5 Gravimagnetic Parameter.- 4.6 Corotation Radius.- 4.7 Nomenclature.- 4.8 Critical Periods. The p-y and p-L Diagrams.- 5. Boundaries. Magnetospheres of Slowly Rotating Neutron Stars.- 5.1 Physical Conditions in the Alfvén Zone.- 5.2 Formulation of the Problem.- 5.3 Simple Configurations.- 5.4 Magnetosphere in Spherically Symmetric Accretion.- 5.5 Pascal's Pressure Law.- 5.7 Magnetosphere in a Plane-parallel Plasma Flow.- 5.8 Two-Stream Accretion.- 6. Accreting Neutron Stars.- 6.1 Boundary Stability.- 6.2 The Polar Column.- 6.3 Spin-up, Spin-down and Induced Precession of Accreting Stars.- 6.4 Observed Properties ofX-Ray Pulsars.- 6.5 Energy Parameters of Pulsars and Transport of Matter in Binary Systems.- 6.6 Spectrum and Magnetic Fields.- 6.7 Periods of X-Ray Pulsars and Their Variation.- 6.8 Variability of X-Ray Sources. Transients.- 6.9 Generation of Relativistic Particles.- 6.10 X-Ray Bursters.- 6.11 Nuclear Burning at the Surface of Neutron Stars. Spherically Symmetric Model.- 6.12 Accretion to X-Ray Bursters.- 6.13 Spinning-up of Weakly Magnetized Neutron Stars.- 6.14 Low-Mass X-Ray Sources. "Noisars".- 6.15 p-y Diagram for Accreting Neutron Stars.- 7. The "Propeller" Regime.- 7.1 Quasistatic Shells.- 7.2 Spinning-down in the Boundary Layer.- 7.3 Two-Stream Flow Formation due to the Propeller Effect.- 7.4 Dead Disks and Accumulator Disks.- 7.5 Nonstationary Disk Accretion. Model of Transient X-Ray Sources.- 7.6 Relativistic Propeller.- 7.7 Objects That Can Become Propellers.- 8. Ejecting Stars.- 8.1 Observed Characteristics of Radiopulsars.- 8.2 Radiopulsars as Ejecting Neutron Stars.- 8.3 Pulsar Electrodynamics and Generation of Relativistic Particles.- 8.4 Mechanisms of Radiation.- 8.5 Caverns Around Neutron Stars.- 8.6 Change in Radiopulsar Period.- 8.7 Evolution of Radiopulsars.- 8.8 Spatial Velocities of Radiopulsars.- 8.9 Ejecting Stars in Binary Systems.- 9. Supercritical Regimes.- 9.1 Superaccretor.- 9.2 Superejectors and Superpropellers.- 9.3 Is SS 433 a Superaccretor?.- 9.4 Other Candidates.- 10. Stars with an Anomalously Low Value of Gravimagnetic Parameter.- 10.1 Georotators.- 10.2 Binary Magnetic Systems (Magnetors).- 11. Evolution of Stars.- 11.1 Normal Stars.- 11.2 Evolution of Neutron Stars.- 11.3 Neutron Star Tracks.- 11.4 Numerical Simulation of the Joint Evolution of Normal and Neutron Stars.- 11.5 Possible Candidates.- MagnetohydrodynamicInstabilities.- Rayleigh-Taylor (RT) Instability.- Commutation Instability.- References.