 The purpose of this article is to delineate further the various questions pursued under the rubric of “units and levels of  selection.”[1]  Four quite distinct questions will be isolated that have, in fact, been asked in the context of considering, what is a unit of selection? In  section 2,  these distinct questions are described.  Section 3  returns to the sites of several very confusing, occasionally heated debates about “the” unit of selection. Several leading positions on the issues are analyzed utilizing the taxonomy of distinct questions.