The Selectividad is the Spanish university entrance exam taken by students enrolled in a Spanish diploma school. The test has two functions: it is designed as a school-leaving examination but more importantly its actual purpose is to serve as a selection criterion to enter Spanish University. It is Spain's most famous academic qualification, a non-compulsory exam taken by students after secondary school, necessary to go into University. This is the name it used to have years ago, but the official is PAU, Prueba de Acceso a la Universidad (University Access Tests). Students must take 6 exams in three days, consisting of common and specific subjects taken in Bachillerato.