1. An information search apparatus, comprising: an interface configured to obtain a search option input by a user; a processor; and a storage device configured to store a plurality of instructions which causes the processor to perform searching when the search option is obtained through the interface, wherein the processor is further configured to: determine a search term based on the search option, the search term including an extracted search term that is extracted from the search option; search a document database to obtain a document that matches the search term; generate a search result including document information identifying the document that matches the search term and relevancy information indicating a degree of relevancy between the search term and the document; cause a display device to display the search result in a format indicating the correspondence relationship of the document information, the search term, and the relevancy information, wherein the format indicating the correspondence relationship is a matrix, the matrix including a cell that represents relevancy information between the search term and the document, the matrix is displayed on the display device, and the cell, which is linked to the document, is configured to be activated by a user input and to cause the display device to display at least a portion of the document having the search term with the search term displayed in the document differently from other words in the document, wherein the matrix includes a row including a matrix element representing one of the search term or the document information, a column including a matrix element representing another one of the search term or the document information, and the cell being provided at a location where the matrix element representing the search term and the matrix element representing the document information meet and indicating the degree of relevancy between the search term represented by the corresponding matrix element and the document identified by the document information represented by the corresponding matrix element, and wherein, when the search term includes a plurality of search terms, the processor is further configured to generate a plurality of search results for each one of the plurality of search terms, and cause the display device to display the plurality of search results in the format indicating the correspondence relationship of the document information, the search term, and the relevancy information for each one of the plurality of search results; and the relevancy information is displayed visually in a graphical image having a shape representing the relevancy information.