Prioritizing state updates
When something happens in our React application, we usually make several state updates so that the UI can reflect these changes. Typically, you can make these state changes without much thought about how the rendering performance is impacted. For example, let's say you have a long list of items that need to be rendered. This will probably have some impact on the UI – while the list is being rendered, the user probably won't be able to interact with certain page elements because the JavaScript engine is 100% utilized for a brief moment.
However, this can become an issue when expensive rendering disrupts the normal browser behavior that users expect. For example, if the user is typing in a textbox, they expect the character they just typed to show up immediately. But if your component is busy rendering a large item list, the textbox state cannot be updated right away. This is where the new React state update prioritization API comes in handy...