What are state preservation rules in hot reloading?

Below are the state preservation rules in hot reloading,

1. When editing the <template> of a component, instances of the edited component will re-render in place, preserving all current private state.
2. When editing the <script> part of a component, instances of the edited component will be destroyed and re-created in place.
3. When editing the <style> hot reload operates on its own via vue-style-loader without affecting application state.