The most obvious difference is in the resolution, which is the number of individual pixels that make up the image on the screen.
A 3DLP native, or true 4K projector achieves the full 4K resolution pixel count of 4096 pixels wide by 2160 pixels high.
By comparison, 4K UHD images are 3840 pixels wide by 2160 pixels high. A 1DLP or 3DLP 4K UHD projector uses pixel-shifting technology to rapidly shift pixels in the projected image by a fraction of a pixel to simulate 4K UHD resolution which is higher than the projector’s native resolution.
4K UHD images are visually appealing and detailed, meeting the needs of many applications. However, 4K UHD images have a slightly softer appearance than a native 4K image, which provides a higher level of detail and sharpness and a higher pixel density to provide a more lifelike, immersive visual experience.