A network system is provided with a plurality of terminals connected thereto, each of the terminals being configured to be connectable to a network and switchable between server mode and client mode. Each of the terminals includes a terminal information registration unit and a comparison information storage unit, and the terminal information registration unit stores information on each other terminal connected to the network as well as information on whether each other terminal is a server terminal or a client terminal. The comparison information storage unit stores comparison information used for server selection. In a server selection process, at least one of the terminals compares pieces of the comparison information stored in the comparison information storage units of the individual terminals through terminal-to-terminal communication and, depending on the result of comparison, one of the terminals to which priority is given is selected to work as the server terminal.