Ray tracing tells you what the light hit. PBR tells you what happens to the light when it hits something. They can be used separately or together. For example

Ray tracing tells you what the light hit. PBR tells you what happens to the light when it hits something. They can be used separately or together. For example you can use PBR with rasterization instead of ray tracing (which describes many modern games), and you can use ray tracing with simplified or non-realistic materials (e.g. toon shading) instead of PBR materials. Also, the term "PBR" has generally come to mean a set of specific techniques and equations that are still a radical simplification of what happens in the real world. These techniques are a good approximation in many cases but some materials will not be well modeled by the typical PBR equations. There are more advanced material models that can be used. These are often published at SIGGRAPH.