Information processing system using information caching based on user activity

An information processing system in which the necessary information can be transferred via a network by the time this information becomes actually necessary, without damaging the utility and convenience from the user's point of view. An information transfer to a first information processing apparatus from a second information processing apparatus via a network is realized by predicting a necessary information which will be required by a user using the first information processing apparatus in future and a necessary time by which the necessary information will be actually required by the user, according to a knowledge concerning an activity schedule of the user; and controlling the transfer of the necessary information from the second information processing apparatus to the first information processing apparatus via the network such that the necessary information will be transferred by the necessary time.