First of all, the word "proxy" describes someone or something acting on behalf of someone else.
In the computer realm, we are talking about one server acting on the behalf of another computer.
Acting on behalf of client (browser)
- serves Users: help Users access the Server
- grant the client anonymity
https://github.com/Rob--W/cors-anywhere
Acting on behalf of server
- serves Server, protect Server from user
- grant back end servers anonymity