1. A method of collecting information of interest to a user about multimedia content, the method comprising: receiving, from a plurality of multimedia terminal devices, user-selected first content about the information of interest to the user among the multimedia content; collecting metadata of the first content by parsing a resource using a uniform resource identifier (URI) of the first content; extracting at least one first information object including a schema according to a search category from the collected metadata; storing the first information object in a first database, which is independent of the plurality of multimedia terminal devices, collecting web data from an external multimedia service including a web service by using a uniform resource locator (URL); extracting at least one second information object from the collected web data; storing the extracted second information object and additional information about the second information object in a second data base; and mapping the first information object to the second information object, wherein: the first information object is categorized according to a type of a plurality of multimedia terminal devices which searches for the first information object, and the mapping of the first information object to the second information object comprises: comparing a URI of the first information object with a URI of the second information object: registering the first information object in the first database if the second information object, which is the same as the first information object, does not exist in the second database; connecting the first information object to the second information object if the second information object, which is the same as the first information object, exists in the second database; and storing at least one piece of additional information about the second information object and the first information object together in the first database.