useTrasition() and useDefferedValue are two new hooks introduced in React 18. They appeared to be great tools for making more smooth UI. Moreover, they use concurrent rendering in React which allows developers to create much better UX for apps. As far as these two are new hooks, some devs confuse them and try to compare them. For this reason, we will disclose the usage and meaning of useTransition() and useDefferedValue() and give a short glance at concurrency itself.