With advances in lasers, optics, and electronics, many new 3D display technologies have been proposed with prototypes in research labs or have entered the marketplace. Although some of these technologies (such as Stereoscopy) are familiar to people, other technologies, such as holography, remain far-fetched to most. This survey introduces the principles of current popular 3D display technologies, which are generally categorized into four categories: 3D movies, on-stage holograms, holographic projections and volumetric 3D displays. Furthermore, the limitations of each of the aforementioned technologies are deeply analyzed, and comparisons of these technologies are provided. Moreover, we note appropriate application situations for the various technologies. Because computer-generated hologram (CGH) technologies are considered to be the next generation of 3D display technology and have become a dominant direction in 3D display technology development, we address the challenges that CGH is currently facing and provide an insightful analysis of solutions proposed in recent years. Finally, we study the current 3D display applications associated with the four categorized technology principles.