MIP DIP VIP. I am sometimes confused with the NAT names of the Juniper ScreenOS devices. Therefore, I drew a small figure with a few basic examples for these NAT types.
During my job I am frequently discussing with people why they use NAT or why they believe that NAT adds any security to their networks, mainly some obscurity as NAT (PAT) hides the internal network structure. However, NAT does not add any real security to a network while it breaks almost any good concepts of a structured network design. To emphasize this thesis, here is a discussion: