synchronisation only results in incremental changes being recorded between the two locations continuous monitoring of file structures to detect changes is not necessary when the present invention is used and the capability to synchronise files in more than two locations provides additional possibilities for ways of managing data additionally when data stores on two computers are being synchronised the synchroniser software is required to run on only one pc to achieve synchronisation typical examples of transfer where a user may require files stored in accessibly more than one location include for example having a laptop computer and a desktop computer or two desktop computers at different locations for example a home computer and one in an office it is also necessary to maintain computer backups so that a working copy can be synchronized to a back up from time to time users of the internet may wish to maintain an listing of favorite urls for example on more than one computer and where a service provider or website owner has a published website it is possible to update the published website to reflect information held in a development website for example only a small fraction of files may be updated deleted or new files created at one of the locations leading to inefficiencies in copying and network usage where the synchronisation is effected across a network thus the synchroniser reduces the amount of network traffic because only materials which have been updated are changed therefore reducing both the time and cost of effecting an update referring now to fig1 in fig1 a.