ReactJS is ideal for creating large applications that use data that changes over time. It makes it easier for developers to manage complex states and sections of the application. It is also used for creating high-performance applications, since it allows for more fluidity between components and elements.
ReactJS is an incredibly versatile library, and it can be used for almost any kind of application. React has become so popular that companies like Airbnb, Netflix, Uber, and even the US Army use it. It has become the go-to solution for developers who want to build fast, efficient, and dynamic user interfaces.
At its core, ReactJS is all about reusing HTML components and being able to integrate outside components and analytics easily. It encourages developers to create components with minimal lifecycle events (state-management) as if they were templating systems.