Student groups at Columbia span a wide range of interests including fraternities, sororities, club sports and student government organizations.
Groups that are "recognized" by one of the established governing boards receive funding and other benefits. There are estimated to be over 400 recognized undergraduate student groups.
And furthermore, several academic departments and administrative offices host student organizations that are not recognized by the system of governing boards. Departmental recognition is often a first step to later recognition by one of the governing boards (why limit yourself to just one budget?).
In addition to the "recognized" and otherwise official groups, there naturally also exists an unknown number of unofficial student groups, which have not pursued recognition, or perhaps failed to achieve it.