An overview of the current state of discussion and realization of local area networks (LAN's) is presented. After an introductory classification of LAN's, the article presents the basic concepts concerning structures and protocol hierarchies for local area networks in the narrower sense, e. g. LAN's as standardized by IEEE. The differentiation from personal computer networks and private branch automatic exchange systems is outlined. Special emphasis is given to the aspect of LAN-integration in existing corporate networks. © 1986 De Gruyter Oldenbourg. All rights reserved.