As you have probably noticed, the Camera Raw words are spread by many other posts. Despite its significant amount of functions, I mainly use it as a last resource for basic color corrections. Sometimes people get confused because of the Raw word. It makes them think it will only work with RAW files, but you can set it to open other formats such as JPEG.
Interface & Adjustments
If you ever worked with photoshop layer adjustments, then you will recognize part of the options displayed here, such us the ones in the Basic tab. The HLS/Greyscale tab also contains really useful options for my renders. In this case, I felt the greens needed to be slightly desaturated and add some yellow to the area. With the HLS/Greyscale tab, I am able to desaturate, brighten and give the greens a more yellowish tone, without changing any other colors.
When it comes to other tabs such as the Detail one that contains the Sharpening and Noise Reduction adjustments, I do not use them because I already apply the denoiser element to my render setup. As for the sharpening, I prefer to use the Structure definition in Viveza 2 through the Control points. I could actually use the Preset tab to save a few predefined setups, but the use of Camera Raw by me is specific and there are times that it is not needed at all.
Same as the Nik Collection Suite plugins, you need to work a few times with Camera Raw to get the hang of it. There are other plugins like the Lightroom which are quite similar to Camera Raw. If by chance you work with one of them, it will be easier to adapt to the other.