Information providing method which enables data communication costs to be reduced, and information providing system for implementing the method

Abstract

An information method and system enables information, from a set of original information which is updated at regular or irregular intervals, to be provided to each information receiving apparatus of respective users via a data transmission path which can be selected in accordance with the type of data to be transferred, stated preferences of the user with regard to providing of data, current operating status of a data communication network, etc. A set of framework data are selected as data which are rarely updated, by monitoring original information that is to be provided, over a suitably long period, and are stored at the information providing apparatus and each information receiving apparatus. Thereafter until a new set of framework data are selected, any differences between newly updated original information and the framework data are obtained as variation data, and transmitted to be stored at each information receiving apparatus, which can reconstitute desired data on request from a user by combining appropriate parts of the locally stored framework and variation data, thereby minimizing the amounts of data which must be transmitted to the information receiving apparatuses.