The Moodle Assignment Activity allows you to create an assignment in Moodle that students upload (or enter) into the Moodle course itself. If students are uploading their files to the assignment, you can then download all the student submissions as a single, compressed *.zip file, which you can save to your computer. If you select the "Feedback files" option when creating the assignment, you can also upload a commented version of each student file back into the course, for that particular student to see. In previous versions of Moodle (below 2.3), the Assignment activity had multiple types: Advanced Uploading of Files, Online Text, Upload a single file, etc. You chose the particular assignment type based on the features you wanted for the assignment. For example, "Advanced uploading of files" was the most flexible assignment type. It allowed students to upload more than one file to an assignment, and it allowed the instructor to return a commented version of the file back into the assignment for each student, as we have described. However, the "Advanced uploading of files" assignment type had a default setting of "Enable send for marking" that required students to click on an additional button in order to finalize their submission, and the instructor had to release the file back to the student if s/he made a mistake when submitting the file. Another problem with the Moodle 2.2 (and below) assignment types is that you couldn’t change the type of assignment once you had selected a particular type. If you realized that you wanted to use a different assignment type, you needed to recreate the assignment.
With Moodle 2.3 and above, Moodle introduced a unified assignment type that allows you to create an assignment and then choose the particular properties of that assignment as you specify the assignment details. Among those assignment options is a new "group submission" feature that allows you to have one member of a pre-created group upload the assignment for the group, with all members of the group able to view the comments and the grade you provide. The new unified assignment type also allows for more flexible grading of assignments. With Moodle 2.2 (and below) assignments, you chose a whole number grade from a drop-down list of possible grades. With the unified assignment type, Moodle gives you a text box to enter grades, allowing you to enter whole-number grades or partial grades (such as 3.5 out of 5, for example).
We recommend that you choose the new unified assignment type when creating assignments in Moodle, unless you want to create a TurnItIn assignment that will check the student submissions against a database of previously submitted and publicly available work, to determine the "originality" of the student work. The following image shows the assignment choices you will see after you click on "Add an activity or resource" in the bottom-right corner of a topic block:
See this video for a more detailed tutorial on creating assignments using the new unified assignment activity in Moodle.