Can someone explain these two

[francis11]

- Templates
I also suggest to use NTLite Templates from the scratch, no presets to begin with while getting to know the tool.
You can pick Gaming or Lite, I use Printing compatibility enabled with the Lite template and Printing works.
Of course don't disable extra services or add external tweaks while preparing the initial test.
Once you have it working, remove further only if some component annoys you, for example I also add Defender to the removals, which is not in the templates as it can be considered as a free good enough antivirus - still thinking should it be added to the Lite preset.

- Compatibilities
Very important to go through Compatibilities and enable those you need, and as francis11 stated, Recommended (red) components is the one to lock for sure.
Host refresh compatibility is another must to enable, because it gives you a method to easily return components without reinstalling all, in most cases.
Start with all (or at least don't uncheck the default) compatibilities enabled if unsure, there is VPN one etc. Since NTLite can remove live as well (from C:\Windows), you can trim more later, use backups or test in a virtual machine when exploring.

- Remove more later
Once you learn what you (or your apps) need, you might reach crazy tistou77 levels of ~1500 removed components, I am around a 1000 as I have a lot of development apps and need to test updating which requires more to keep. I bet our biggest difference is in driver removals, where I don't have patience to filter INF by INF

Scanner gets protected with NTL Printer Compatibility but is not needed if using a PDF program like Adobe or Nitro and maybe other have build in scanner option.