Redux Slice

A slice is a collection of reducer and action logic for a single feature of an application, often arranged in a single file. For example, all the reducer logic related to the counter is in counterSlice.

A slice may also refer to a part of the application state for a specific feature, hence the name slice. A Redux state can be divided into multiple slices. In a chat application, the Redux Store might look like this:

Here posts, comments, and reactions are separate slices of the Redux state, handled by the slice reducers postReducer, commentsReducer, and reactionsReducer, respectively.

A Slice Reducer is a reducer associated with a specific slice. For example, postReducer is called a slice reducer for postSlice. It can also be referred to as a 'reducer' in more general terminology.

A slice in a Redux store creates a portion of a state defined by the assigned key name, which is managed by a specific reducer (slice reducer). In the previous chapter, you were given the task of creating a slice using the reducer from todosSlice:

The overall state of this application might roughly look like this:

Since the above application has only one slice, it has only one section called todos. We can create more slices:

The state might look something like this:

Since we have not looked at what's inside the todosSlice file, we cannot tell what data will be in there initially. In the next chapter, it will become clearer.