With Redux, your app is kept in a state store, and each component can access any state it needs from this store. Let's take a little deeper look to see why you might need the Stete management tool.
Why do you need Redux?
Most libraries, such as React, Angular, etc., are created in a way for components to manage states internally without the need for an external library or vehicle. A few component works well for applications, but as the app grows, managing states shared between components becomes a chore.
In an application where data is shared between components, it can be confusing to know where a data should be. Ideally, data in a component must be a single component, making data sharing difficult between sister componentes.
For example, in React, to share data between siblings, a data must live in the main component. One method for updating these states is provided by the main component and passed as support for these sibling component. This makes it easier for us to manage data.
If you want more information, you can review redux's site