Deferring expensive values

A deferred value lags behind the real one on purpose, letting the urgent render finish first with the previous result.

What this lesson covers

• Defer a value that drives expensive rendering
• Choose between deferring a value and wrapping an update
• Communicate staleness to the user while it catches up

This lesson sits in Concurrent React, part of React Performance Engineering. It assumes what came before it and leads directly into the next lesson in the module.