An inside global address is a registered IP address assigned by the ISP that represents internal local IP addresses externally.

An inside local address is an IP address (usually private) assigned to a host on the internal network. The inside local address is usually not assigned by the service provider, nor used to represent one or more inside local IP addresses externally

An outside local address is the IP address of an outside host as it appears to the internal network. It is not used to represent one or more inside local IP addresses externally.

An outside global address is the IP address assigned to a host on the external network by the host owner. The address is allocated from a globally routable address space. It is not used to represent one or more inside local IP addresses externally