为什么我们在同一个项目中同时使用 Redux 和数据库（Mongo atlas）？

Question

since both acts as Centralised storage which helps us to update and retrieve data, and why people update/delete data from database as well as redux since redux fetching data from database itself right

Answer 1

Simply, database is the storage for the server and Redux is global state store for the browser.

Suppose you have the service that has 100,000+ users.

Redux cannot hold such size of data and if can hold the data, you shouldn't do so because user data must be kept safely in to your server.

Instead, let the API server fetch a single user data from the database for the HTTP request and let the Redux hold the single userdata to keep the login context.

To do so you can kept userdata safe and also keep the login context for the browser