This document discusses the client-server model and how it relates to concurrency and processes in computer networks. It begins by comparing the OSI and TCP/IP models, then defines the client-server model and shows examples of the client-server relationship. It next covers concurrency, describing different types of servers like connectionless iterative and connection-oriented concurrent servers. Finally, it discusses processes, showing how programs and processes relate, examples of getting process IDs, and how forking allows a program to create parent and child processes like in a server program.