React is currently the leader in JavaScript UI frameworks. First, the Facebook developers started working on this to make their job easier. An app called Facebook Ads grew very quickly, which meant complex management and support. As a result, the team began to create a structure that would help them with efficiency. They had an early prototype before 2011, and two years later, the framework was open source and available to the public. It is currently used by many business giants: AirBNB, PayPal, Netflix, etc.