1. An apparatus for outputting information comprising: a computer readable storage medium; a terminology-information storage unit; a history-information storage unit; a term extracting unit that extracts terms contained in a text from each of a plurality of texts; a first storage control unit that stores, in the terminology-information storage unit, the terms extracted in association with text identification information of the text that contains the terms; a history-information acquiring unit that acquires history information indicating a history of operations performed by users on the text; a second storage control unit that stores, in the history-information storage unit, history information in association with user identification information of each of the users who has performed an operation and the text identification information of the text subjected to the operation; a usage-frequency calculating unit that calculates, for each of the user identification information, a frequency of usage of each of the terms contained in the text, which is identified by the text identification information that is associated with the user identification information, based on the terms stored in the terminology-information storage unit for each of the text identification information; a term selecting unit that calculates, based on the frequency of usage of each of the terms, a relative difference between a specific user identification information and other user identification information contained in the user identification information of the users and selects terms for which the difference is equal to or larger than a predetermined value; and an information outputting unit that outputs the terms selected to an output device, wherein the term selecting unit selects the terms for which the frequency of usage for the user identification information of the specific user is lower or higher than the frequency of usage for the user identification information of the other users, with respect to the user identification information of the specific user and that of the other users stored in the history-information storage unit, based on the frequency of usage of each of the terms, a user selecting unit that selects an user identification information for which the frequency of usage for each of the terms selected by the term selecting unit is equal to or larger, or equal to or smaller than a predetermined value from among the user identification information of the other users, wherein the information outputting unit outputs the terms selected by the term selecting unit and the user identification information corresponding to the terms in association with each other.
3. The apparatus according to claim 1 , wherein the information outputting unit outputs the terms selected by the term selecting unit in descending order of number of texts that contain the terms.