Nvidia's new RTX technology may bring real-time ray tracing to gaming and other media. Ray tracing results in incredibly realistic lighting, which has long been a difficult process for most game engines to handle in real-time. In its current form, RTX is only compatible with Nvidia's Volta-based GPUs.
https://www.notebookcheck.net/Nvidia-s-RTX-real-time-ray-tracing-promises-to-bring-lifelike-lighting-via-Volta-GPUs.289944.0.html