Assignment 
Assignment sub-types allow new types of assignments to be developed (note that these may be deprecated in future versions of Moodle, in favour of making them full activity modules).
Join the discussions about assignment plugins in the Assignment activity forum.
Sub categories
Different forms of assignment submissions (Moodle 2.3 onward)
Different forms of assignment feedbacks (Moodle 2.3 onward)
Assignment types (8)
Different forms of assignments to be graded by teachers (Moodle 2.2 and earlier - /mod/assignment)