(just following Ben around...) See the documentation FAQ http://docs.moodle.org/22/en/Groups_FAQ#What_is_the_difference_between_a_cohort_and_a_group.3F
(just following Ben around...) See the documentation FAQ http://docs.moodle.org/22/en/Groups_FAQ#What_is_the_difference_between_a_cohort_and_a_group.3F