HAIRY BOY

The purpose of NAT is to assign unique public/ legal IP address to the clients.
Therefore, all the private IP addresses will be converted to legal IPs, which are recognized publicly! There are two methods of NAT: Static and Dynamic
Static way is to assign a static/fixed IP for an individual.
Dynamic way is to assign random IP address from a pool/range of IP addresses.
PAT (Port Address Translation) is used to connect larger number of clients but limited to user a single IP address with the help of various port numbers. This is best used in the Class A private IP scenario to Class C Public IP address. [ In CISCO, this is also known as NAT Overload ]