A true library network is the interfacing of more than one kind of system (i.e., public and academic) rather than cooperation between libraries of the same type. Networks may take many forms, such as: cooperative development of resources, with assignment of subject areas to separate facilities; a cooperative storage system, with the libraries contributing materials as well as central acquisitions of them; centralized processing, which has had many failures due to inadequate funding and processing delays; cooperative computer uses, for card production from MARC tapes, maintenance of data bases, or creation of union lists of serials; and regional sharing of resources for access to little-used materials. (One of the more successful networks now operating is the Ohio College Library Center.) Communication between network units may be by facsimile (which is most expensive), telephone, TWX, microwave network, or satellite. Access may be by interlibrary loan or copy. Some problems have been: patrons want material immediately, without delay; and questions of copyright have not been resolved. Bibliographic access, whether by cards, computer, or printed lists, is the key to network operation. (LS)