It is not a currency, it is a NAT mapping table on the NAT gateway, which records the conversion of private network IP corresponding to each public network IP. (NAPT) adds the concept of the port. Each private network IP corresponds to different port numbers of the same public network IP, so that multiple private network IPs can share a public network IP. The outer network is to access your internal network host. The destination address is the public network IP and the port number that represents you (here also involves a problem of mapping back, that is, port mapping).
It is not a currency, it is a NAT mapping table on the NAT gateway, which records the conversion of private network IP corresponding to each public network IP.
(NAPT) adds the concept of the port. Each private network IP corresponds to different port numbers of the same public network IP, so that multiple private network IPs can share a public network IP. The outer network is to access your internal network host. The destination address is the public network IP and the port number that represents you (here also involves a problem of mapping back, that is, port mapping).