Can you explain the difference between server-side and client-side state management? What are libraries like Tanstack Query used for?

Server-side state management is responsible for storing and managing data state on the server, such as in a database or cache. Client-side state management involves managing the state directly within the application on the user's device (in the browser or mobile device).

Libraries like Tanstack Query (formerly React Query) are designed for convenient management of asynchronous server requests, caching, updating, and synchronizing data on the client. They help abstract away low-level network details, provide automatic data updates, retry mechanisms, and performance optimization.

Example of using Tanstack Query in React:

import { useQuery } from '@tanstack/react-query';

function UserProfile({ userId }) {
  const { data, error, isLoading } = useQuery(['user', userId], () =>
    fetch(`/api/users/${userId}`).then(res => res.json())
  );

  if (isLoading) return <div>Loading...</div>;
  if (error) return <div>Loading error</div>;

  return <div>User name: {data.name}</div>;
}