1. A server apparatus, comprising: a communicator configured to receive a text which corresponds to a voice signal; and a controller configured to, in response to a keyword, which corresponds to the text, not existing from among at least one keyword included in a mapping table, search for content information belonging to a content genre mapped with a synonym of the text, provide a search result to a display apparatus through the communicator, and update the mapping table by adding the synonym as the keyword, wherein the mapping table is a table in which the at least one keyword, at least one content genre, and at least one priority score in combination are mapped, and wherein the controller, in response to a plurality of content genres being mapped with respect to the synonym, selects at least one content genre according to a priority determined with respect to the plurality of content genres, and searches for content information belonging to the selected at least one content genre.