VoIP Number Spoofing and Cleaning Process: How Does It Work

hello.
I have been hearing from some people I know that certain VoIP numbers are being cleaned and renamed (or spoofed) on platforms like Hiya and TrueCaller. I would like to understand how this process works. Specifically, how are these numbers "cleaned" and how do they get renamed? Does anyone have knowledge of this process or experience with it? Any help would be greatly appreciated