There are many types of activities available in Moodle: several types of assignments, activities for communication and collaboration between you and your students, quizzes, polls and surveys, tools to aid in managing students, and formats for delivering interactive content.
Moodle provides several ways to track and collect work from students. You can have them submit files or enter content into a text box. You can also assign "offline" work not submitted through Moodle (but that can be graded in Moodle). You can configure how many files a student may submit, the maximum file size allowed, and set deadlines and cut-off dates. You can exchange comments with individual students about their submissions, grade (with the option to use a Rubric, Grading guide or Simple direct grading), and leave written feedback.
Turnitin helps instructors evaluate the originality of student work by comparing submitted files to online sources and the Turnitin database. The software returns an Originality report which rates submitted assignments and highlights text that appears elsewhere. Turnitin also provides a suite of feedback tools, including the ability to grade using a Rubric, and add notes or comment clips directly to student submissions. Grades awarded in Turnitin are automatically transferred to the Moodle gradebook.
External tool(s) allow students to interact with certain learning resources and activities on other web sites. For example, you can link to OWL or to learning materials from a publisher. To setup an external tool instance, a tool provider which supports LTI (Learning Tools Interoperability) is required. The tool provider should be able to provide instructions on how to configure the external tool for their site.
Instructors and students can communicate and collaborate using Forums, sometimes called "discussions." Instructors can create topics or, depending on the Forum type, allow students to originate topics, to which course members can "post" a reply.
Workshop is a peer assessment activity with many options. Students submit their work via an online text tool and attachments. Students receive two grades in this activity, one for their own work based on peer reviews and another for their peer assessments of other students' work.
Moodle quizzes are comprised of a Quiz activity that contains one or more questions from your course's Question bank. The Quiz activity lets you administer a wide range of question-types within a specific layout and order, provide different kinds of feedback based on how a student performed on the quiz, and control how students access the quiz.
Questionnaire activity allows you to survey your students using a wide range of question types. For example, you can collect student feedback on your course or on a particular topic. In a Questionnaire, individual answers cannot be graded, but you can award a grade for the entire activity.