The May 1985 issue of the IEEE Journal on Selected Areas in Communications is devoted to the topic of communications for personal computers (PC). The present authors intend an overview of computer communications, relying mostly on material in the ten JSAC papers. The work follows a layered approach in reviewing PC communications and contrasting the points of view presented in the JSAC issue on this subject. First, connection media are reviewed. Secondly, the network architecture used to provide multistage paths across the network, and the higher level communications functions are examined. Finally, a systems view is taken to discuss the key services which can be made available to PC users and to application programs when the PC participates in a network.