Middleware in Redux refers to a function placed between the action being dispatched and the action reaching to the reducers in Redux. It provides a third-party extension point between dispatching an action, and the moment it reaches the reducer.
Middleware can be used for a variety of tasks such as handling asynchronous actions, logging every action, handling error etc. Middleware sits in the middle of all dispatched actions and handles complex logic in a consistent, composable way. It provides a way to interact with actions that have been dispatched to the store before they reach the store’s reducer.