10. The data display server according to claim 6 , wherein said relational data is displayed in a descending order of a degree of relevancy representing how strong said relational data bears a relationship with said item data.
6. A data display server connected to a user terminal to display prescribed data in response to a request through the user terminal, said data display server comprising: a reference database that holds item data configured to be referred to by a user; message creating means for permitting the user to create, through the user terminal, a message to be posted; keyword input means for permitting the user to input, through the user terminal, a keyword of reference data about contents of the message; item data retrieving means for retrieving the item data from the reference database by the keyword; item data juxtaposing means for juxtaposing and displaying, on a display of the user terminal, one or more pieces of item data resulting from the retrieval; item data selecting means for permitting the user to select, through the user terminal, the item data attached to posting data from the displayed item data; posting means for permitting the user to post, through the user terminal, the posting data containing an item data ID of the item data selected by the item data selecting means; a posting database that holds the posting data including (i) the posting message, a posting ID identifying the posting message, and the item data ID having been posted through the user terminal and (ii) responsive posting data including a responsive posting message, a posting ID identifying the responsive posting message, and an item data ID; posting browsing means for displaying, on the display of the user terminal in response to a posting data browsing request from the user, the posting data and the item data specified by the item data ID contained in the posting data; relational metadata generating means for extracting the item data ID one by one from the posting data and the responsive posting data according to a relationship between the posting data and the responsive posting data to generate relational metadata with the extracted item data IDs contained therein, said responsive posting data posted in response to the posting data posted by said user terminal; and a relational database configured to hold said generated relational metadata; wherein said item data is one or more pieces of information selected from a group comprising the item data ID, an item data name, an alias item data name, a model number, a manufacturer name, a category, a descriptive text, an image URL, a price, and a release date, said data display device further comprising relational data juxtaposing means for juxtaposing and displaying, on a display of said user terminal in response to an item data browsing request from the user, said item data and relational data associated with said item data by said relational metadata wherein said time of relationship to said item data includes one or more relationships selected from a group comprising a way to use the item data, a function, an effect, a combination, similarity and a purchase history, and said relational metadata associates the item data specified by the extracted item data IDs.