6. The system of claim 1 wherein the user interface module is further configured to receive user access requests that specify query tag information, and to retrieve stored files that have been assigned tag information that corresponds to the query tag information by the classification engine.
1. A file classification system, comprising: a content extraction module configured to, in response to a storage request for a file, extract textual content of the file; a classification engine configured to analyze the extracted textual content to determine a first concept category to which the file can be assigned, and to assign tag information corresponding to the first concept category to the file; and a user interface module configured to display the first concept category and receive a selection of a second concept category from a user; wherein the classification engine is further configured to assign tag information corresponding to the second concept category to the file.