Difference between react-hot-loader, webpack-hot-client, webpack-hot-middleware?

Description

More explanation

Environment

React Hot Loader version: recent stable

1. node -v: 8.9.4
2. npm -v: 5.6.0
3. Operating system: Ubuntu 16.04.3 LTS, xenial
4. Browser and version: Chrome 63.0.3239.132 (Official Build) (64-bit)

Question

What is the difference between react-hot-loader and webpack-hot-client (webpack-hot-middleware)?

I'm developing React+Express application. I use Webpack to build assets and compile React. I use webpack-serve as a dev server. This dev server features HMR out-of-the-box (it uses both, webpack-hot-client and webpack-hot-middleware).

Do I need to use react-hot-loader if I use webpack-serve? Why? Could you please explain what exactly react-hot-loader does?