State handling and syncing on the blockchain are the core reasons for blockchain to even work. Because it is a network of nodes that has to agree on what the truth is. Here are some articles that introduces some more context and insight how this is done.
The question around this was: "Exact definition of state and how blockchain solves the issue of maintaining a permanent state. I am aware of how the ethereum blockchain transitions between states (from genesis state to the final/current state), but the idea of state is not resonating with me completely."