alumnado
student body
alumno
student
+
-ado
collective noun suffix
Alumnado means student body and can be thought of as alumno0 (student0) + -ado1 (collective noun1), literally meaning 'a collection of students'.
noun
- student bodyThe student body of an educational institutionEl alumnado protestó contra las nuevas reglas. // The student body protested against the new rules.