Difference between forward proxy and direction proxy and tutorial _ PHP

The difference between forward proxy and direction proxy. Difference between the forward proxy and the direction proxy and the use of the role played in the request client proxy server content server forward proxy needs to set a proxy, request the content service through the proxy server

Difference and use of forward proxy and direction proxy
Role in the request	Client	Proxy Server	Content Server
Forward proxy	You need to set a proxy to request resources from the content server through the proxy server.	In place of the client request content server	Only requests from the proxy server can be obtained and returned.
Direction proxy	No need to set, request resources on the proxy server	There is no resource in itself. the server obtains the content and returns the resource to the client.	Only requests from the proxy server can be obtained and returned.
Purpose
Forward proxy	The typical purpose of forward proxy is to provide a way to access the Internet for LAN clients in the firewall.
	Forward proxy can also use the buffer feature to reduce network usage.
Reverse proxy	A typical purpose is to provide the server behind the firewall to Internet users for access.
	The reverse proxy can also provide load balancing for multiple backend servers or buffer services for slow backend servers.
	The reverse proxy can also enable advanced URL policies and management technologies to make the web pages in different web server systems exist in the same URL space at the same time.
Security
Forward proxy	The forward proxy allows the client to access any website and hide the client itself. Therefore, you must take security measures to ensure that only authorized clients provide services.
Direction proxy	The reverse proxy is transparent to the outside, and visitors do not know that they are accessing a proxy.

The role played by the principal request client proxy server content server forward proxy needs to be set up proxy, request the content service through the proxy server...