The physical picture of the properties of light in squeezed and in other nonclassical states is presented and compared with the properties of light in the classical coherent state. The theoretical basis of the description and the generation of squeezed light is presented, and a practical scheme for obtaining light in other of its nonclassical states is discussed. The general nature of the phenomenon is emphasized, as well as the possibility of its transfer to other fields such as acoustics, mechanics, and various Bose fields.