What does Ezekiel 18:20 mean?

The one who sins is the one who will die. A child won't be punished for a parent's sins, and a parent won't be punished for a child's sins. Good people will be rewarded for their goodness, and wicked people will pay for their wickedness. Ezekiel 18:20 - Modern Text Bible

(This is the core principle: personal responsibility before God. Everyone stands or falls by their own choices.)