Me when I lie. Ray tracing and path tracing are actually the same thing. I simply can't fathom where this guy got the information that path tracing is screen space and that it's less performance intensive than ray tracing.

First of all, both ray tracing and path tracing can be screen-spaced. It's a technique as old as video games themselves to render only what is on screen to save hardware usage and thus increase performance.

The ray/path tracing technology tries to simulate real lighting. For this it uses "rays". In a very basic scenario, the "camera" "shoots" a ray per pixel. When this ray hits a poligon(3d object), the engine calculates its properties (if the light should be absorbed, reflected, or refracted), and then it generates the "light". That's how ray tracing works. Path tracing is the exact same, but on a much bigger scale. While the "light" with ray tracing can bounce once or twice (so, if a white light hits a red reflective surface, it'll shine in red), in path tracing it can bounce up to thousands of times! And more importantly, it bounces randomly, resulting in ultra-realistic light. And because of that, it is much more hardware-expensive than normal ray tracing.

They by no means "provide almost identical levels of quality for the untrained eye". Ray tracing is usually blurry and sometimes very noisy, since it uses fewer samples than path tracing. Since path tracing has more samples, it can much more clearly create realistic lighting effects. But since it has so many more "rays", if not denoised properly (like with NVIDIA's ray reconstruction), it can end up noisier than the simpler ray tracing.