General properties of neutron stars are briefly reviewed with an emphasis on the indispensability of general relativity in our understanding of these fascinating objects. In Newtonian gravity the pressure within a star merely plays the role of opposing self-gravity. In general relativity all sources of energy and momentum contribute to the gravity. As a result, the pressure not only opposes gravity but also enhances it. The latter role of pressure becomes more pronounced with increasing compactness, M/R, where M and R are the mass and radius of the star, and sets a critical mass beyond which collapse is inevitable. This critical mass has no Newtonian analogue; it is conceptually different from the Chandrasekhar limit in Newtonian gravity, which is attained asymptotically for ultra-relativistic fermions. For white dwarfs the general relativistic critical mass is very close to the Chandrasekhar limit. For neutron stars the maximum mass so called Oppenheimer-Volkoff limit is significantly smaller than the Chandrasekhar limit. This follows from the fact that the general relativistic correction to hydrostatic equilibrium within a neutron star is significant throughout the star, including the central part, where the mass contained within the radial coordinate, m(r), and the Newtonian gravitational acceleration, Gm(r)/r(2), is small.