Explain the Network protocols
There are a wide variety of network protocols to choose from traditionally client - server developers were required to choose a communications protocol and then code by hand the interaction of client and server.
Developers were forced to make difficult choice to support either specific target environments (IPX/SPX on Windows, TCP/IP for UNIX) or support as many network protocols as possible for all environments. The latter is a tremendous burden to undertake from a development standpoint.