NAT mode: "Network Address Translation", which allows a whole organization to appear on the Internet with a public IP address. As the name suggests, it is a technology that NAT forwards internal private network addresses (IP addresses) into legitimate public network IP addresses.
Routing mode: All data is not forwarded by NAT, and the intranet IP is directly transmitted to the external network without masquerading. This mode is suitable for use when all intranet IPs are public addresses.