Okay, so let's imagine that you have a toy named "Teddy". Everyone knows that the toy is called "Teddy" and when you say "Teddy", people know what you mean.
But one day, you start calling your toy "Bear" instead of "Teddy". You keep calling it "Bear" all the time and now your friends are confused because they don't know what you are talking about.
This is kinda like the "rectification of names" concept. In ancient China, it meant naming things correctly so that people could understand each other better.
If you call things by their correct names, then everyone knows what you're talking about. But if you start using different words, things can get confusing and people might not understand you.
So it's important to use the right words and names to make sure that everyone understands each other.