The server device includes: an allocation unit for allocating a unique identifier to each of first data and second data; a management unit for managing a correspondence between the identifier and a method for accessing the first data or second data identified by the identifier; a presentation unit for presenting the identifier managed by the management unit to the client device; a conversion unit for converting an identifier-specifying request for access to the first data or second data from the client device into a method for accessing the first data or second data corresponding to the identifier using an access method associated by the management unit with the identifier; and a data access unit for requesting access to the first data or second data using the access method converted to by the conversion unit, and sending an access result to the client device.