Redux is an open-source JavaScript library for managing application state. It is often used with React, a popular JavaScript library for building user interfaces, but can be used with any other JavaScript framework or library as well.
At its core, Redux is a state management library that provides a predictable, centralized, and immutable way to manage the state of an application. It achieves this by enforcing a unidirectional data flow, where data flows in a single direction from the source of truth (the Redux store) to the components that need it.
The Redux store is a plain JavaScript object that holds the application state. The state can only be modified through actions, which are plain JavaScript objects that describe what happened in the application. Reducers are pure functions that take the current state and an action and return a new state based on the action.
In addition to its core features, Redux also provides a number of other features and extensions that can enhance the functionality of the library, such as middleware for handling asynchronous actions, and tools for debugging and testing.
Overall, Redux provides a powerful and flexible way to manage application states in a predictable and centralized manner, making it a popular choice for building complex and scalable applications.