To shorten the time needed for file transfer and to shorten the time up to a display of the latest information of a homepage by incorporating update information in homepage information of a worldwide web(www) and managing the update history, and extracting difference information between different versions.

When the constitution information part of a homepage A is present in a homepage information storage part (cache), a user-side browser requests the server to transfer the constitution information part of the homepage A and obtains it (202). The browser side compares the constitution information obtained from the server with the constitution information part stored in the cache and can specify elements changed in constitution (203). The browser side requests only the changed elements of the server (204) and reads other unchanged elements out of the cache (205), so that information of the homepage A of the latest version can be displayed (206).