What is the difference between NAT,PAT and reverse proxy?

NAT is divided into static NAT, dynamic NAT and PAT

1. Static NAT: It is a one-to-one mapping of private ip and public ip, and the port number does not change. It is generally used for local area network Internet access.

Dynamic NAT: It is a many-to-many mapping of multiple private IPs and multiple public IPs (address pools), and the port number does not change. When the legal IP address provided by the ISP is slightly less than the number of computers inside the network. Dynamic conversion can be used.

3. PAT: refers to changing the source port of outgoing data packets and performing port translation, i.e. Port Address Translation (PAT). Port multiplexing is adopted. All hosts in the internal network can share a legitimate external IP address to access the Internet, thus minimizing IP address resources. At the same time, it can hide all hosts inside the network, effectively avoiding *** from the internet. Therefore, port multiplexing is the most widely used method in the network at present.

PAT and nginx reverse proxy implementations have the same effect.