This lecture covers the concept of sky surveys in the radio universe, explaining observations of the universe, celestial coordinate systems, equatorial and ecliptic coordinates, celestial spheres, and examples of all-sky surveys like X-ray and CMB maps. It also delves into the size of the target and field of view, observation set-up, sensitivity, types of observations, and examples of optical and radio surveys, such as the NRAO VLA Sky Survey and Meerkat. The lecture concludes with a discussion on 3D mapping of galaxies in the universe.