代理和反向代理的理解(updating)

1、正向代理
我们常说的代理是只正向代理，正向代理的过程，隐藏了真实的请求客户端，服务端不知道真实的客户端是谁，认为代理服务器就是真实的客户端。

2、反向代理
反向代理隐藏了真实的服务端，反向代理服务器会帮我们把请求转发到真实的服务器那里去。我们只知道反向代理服务器，却不知道真实服务器是谁。
Nginx就是性能非常好的反向代理服务器，可用来做负载均衡。

• Nginx 官网给出的解释(2017-07-24 18:38:24)
  

A proxy server is a go‑between or intermediary server that forwards requests for content from multiple clients to different servers across the Internet. A reverse proxy server is a type of proxy server that typically sits behind the firewall in a private network and directs client requests to the appropriate backend server. A reverse proxy provides an additional level of abstraction and control to ensure the smooth flow of network traffic between clients and servers.