Your answer would be, The three categories that TCP/IP divides port numbers into,
Well-known port numbers (0-1023). Reserved for the most universal applications;
Registered port numbers (1024-49151). Other applications that are not as widely used;
Dynamic and private port numbers (49152 - 65535). Available for use by any application.
The TCP/IP protocol suite maps to a four-layer conceptual model known as the DARPA model, which was named after the U.S. government agency that initially developed TCP/IP. The four layers of the DARPA model are: Application, Transport, Internet, and Network Interface.
