The latest generation of NVIDIA graphics cards include hardware-supported ray-tracing, which can dramatically improve the time it takes to render a scene using realistic lighting effects. See more: https://developer.nvidia.com/rtx/raytracing
Ray tracing is an instance of an image-ordered rendering technique, meaning that it works from the pixels on the screen, to objects in a scene, and finally to light sources to determine pixel color values. This would be more efficient for rendering complex scenes than determining which rays emitted by a light source eventually come in contact with the screen i.e. Object-ordered rendering. https://en.wikipedia.org/wiki/Image_and_object_order_rendering
Ray tracing is indeed one of the most fundamental operations in any 3-D application, as a ways of interacting with the environment, not only in photorealistic path tracing - thus, it's definitely important for NVIDIA and other companies to make the operation as efficient as possible.
In response to Aidan's comment, for our Project 3 and for basic path tracing, definitely camera rays are the simpler way to go - however, in the case of path tracing, there exist parasitic scenes where lights are in tight corners, or caustic (glass / metal) rendering whose pixels do not converge in reasonable amounts of time. In this case, techniques such as Bi-Direction Ray Tracing and Photon Mapping are used as a compromise between both object-ordered and image-ordered ray tracing!