>i wanna make a thread asking what umatrix is because i've no idea, but they might laugh at me, so let me try to disguise it as an specific question
Best way to understand it at a basic level is to think of it as a sort of firewall. The same page may both make different types of connections and connect to different places. That's what the grids represent.
To actually answer the 'what' of your question would take a description of a bunch of possible configurations a modern page can have.
If you want to know more about each specific type, just research each of those words in the horizontal list at the top, and read about them.
Otherwise, just block all third parties to be somewhat save, or all scripts and cookies for a more paranoid setup, which will brek 85%+ of common sites