The feedback module enables you to create surveys for your students. Do not confuse this with the survey activity. In survey, you must choose from several pre-made surveys; you cannot build your own surveys. Also, do not confuse this with the questionnaire module. A questionnaire is an add-on, while feedback comes as standard with Moodle.
The feedback module needs to be enabled by the site administrator under Site administration | Plugins | Activity modules | Manage activities.